fallow_core/plugins/

config_parser.rs

//! AST-based config file parser utilities.
//!
//! Provides helpers to extract configuration values from JS/TS config files
//! without evaluating them. Uses Oxc's parser for fast, safe AST walking.
//!
//! Common patterns handled:
//! - `export default { key: "value" }` (default export object)
//! - `export default defineConfig({ key: "value" })` (factory function)
//! - `module.exports = { key: "value" }` (CJS)
//! - Import specifiers (`import x from 'pkg'`)
//! - Array literals (`["a", "b"]`)
//! - Object properties (`{ key: "value" }`)

use std::path::{Path, PathBuf};

use oxc_allocator::Allocator;
#[allow(clippy::wildcard_imports, reason = "many AST types used")]
use oxc_ast::ast::*;
use oxc_parser::Parser;
use oxc_span::SourceType;

/// Extract all import source specifiers from JS/TS source code.
#[must_use]
pub fn extract_imports(source: &str, path: &Path) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let mut sources = Vec::new();
        for stmt in &program.body {
            if let Statement::ImportDeclaration(decl) = stmt {
                sources.push(decl.source.value.to_string());
            }
        }
        Some(sources)
    })
    .unwrap_or_default()
}

/// Extract string array from a property at a nested path in a config's default export.
#[must_use]
pub fn extract_config_string_array(source: &str, path: &Path, prop_path: &[&str]) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        get_nested_string_array_from_object(obj, prop_path)
    })
    .unwrap_or_default()
}

/// Extract a single string from a property at a nested path.
#[must_use]
pub fn extract_config_string(source: &str, path: &Path, prop_path: &[&str]) -> Option<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        get_nested_string_from_object(obj, prop_path)
    })
}

/// Extract string values from top-level properties of the default export/module.exports object.
/// Returns all string literal values found for the given property key, recursively.
///
/// **Warning**: This recurses into nested objects/arrays. For config arrays that contain
/// tuples like `["pkg-name", { options }]`, use [`extract_config_shallow_strings`] instead
/// to avoid extracting option values as package names.
#[must_use]
pub fn extract_config_property_strings(source: &str, path: &Path, key: &str) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        let mut values = Vec::new();
        if let Some(prop) = find_property(obj, key) {
            collect_all_string_values(&prop.value, &mut values);
        }
        Some(values)
    })
    .unwrap_or_default()
}

/// Extract only top-level string values from a property's array.
///
/// Unlike [`extract_config_property_strings`], this does NOT recurse into nested
/// objects or sub-arrays. Useful for config arrays with tuple elements like:
/// `reporters: ["default", ["jest-junit", { outputDirectory: "reports" }]]`
/// — only `"default"` and `"jest-junit"` are returned, not `"reports"`.
#[must_use]
pub fn extract_config_shallow_strings(source: &str, path: &Path, key: &str) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        let prop = find_property(obj, key)?;
        Some(collect_shallow_string_values(&prop.value))
    })
    .unwrap_or_default()
}

/// Extract shallow strings from an array property inside a nested object path.
///
/// Navigates `outer_path` to find a nested object, then extracts shallow strings
/// from the `key` property. Useful for configs like Vitest where reporters are at
/// `test.reporters`: `{ test: { reporters: ["default", ["vitest-sonar-reporter", {...}]] } }`.
#[must_use]
pub fn extract_config_nested_shallow_strings(
    source: &str,
    path: &Path,
    outer_path: &[&str],
    key: &str,
) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        let nested = get_nested_expression(obj, outer_path)?;
        if let Expression::ObjectExpression(nested_obj) = nested {
            let prop = find_property(nested_obj, key)?;
            Some(collect_shallow_string_values(&prop.value))
        } else {
            None
        }
    })
    .unwrap_or_default()
}

/// Public wrapper for `find_config_object` for plugins that need manual AST walking.
pub fn find_config_object_pub<'a>(program: &'a Program) -> Option<&'a ObjectExpression<'a>> {
    find_config_object(program)
}

/// Extract keys of an object property at a nested path.
///
/// Useful for `PostCSS` config: `{ plugins: { autoprefixer: {}, tailwindcss: {} } }`
/// → returns `["autoprefixer", "tailwindcss"]`.
#[must_use]
pub fn extract_config_object_keys(source: &str, path: &Path, prop_path: &[&str]) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        get_nested_object_keys(obj, prop_path)
    })
    .unwrap_or_default()
}

/// Extract a value that may be a single string, a string array, or an object with string values.
///
/// Useful for Webpack `entry`, Rollup `input`, etc. that accept multiple formats:
/// - `entry: "./src/index.js"` → `["./src/index.js"]`
/// - `entry: ["./src/a.js", "./src/b.js"]` → `["./src/a.js", "./src/b.js"]`
/// - `entry: { main: "./src/main.js" }` → `["./src/main.js"]`
#[must_use]
pub fn extract_config_string_or_array(
    source: &str,
    path: &Path,
    prop_path: &[&str],
) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        get_nested_string_or_array(obj, prop_path)
    })
    .unwrap_or_default()
}

/// Extract string values from a property path, also searching inside array elements.
///
/// Navigates `array_path` to find an array expression, then for each object in the
/// array, navigates `inner_path` to extract string values. Useful for configs like
/// Vitest projects where values are nested in array elements:
/// - `test.projects[*].test.setupFiles`
#[must_use]
pub fn extract_config_array_nested_string_or_array(
    source: &str,
    path: &Path,
    array_path: &[&str],
    inner_path: &[&str],
) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        let array_expr = get_nested_expression(obj, array_path)?;
        let Expression::ArrayExpression(arr) = array_expr else {
            return None;
        };
        let mut results = Vec::new();
        for element in &arr.elements {
            if let Some(Expression::ObjectExpression(element_obj)) = element.as_expression()
                && let Some(values) = get_nested_string_or_array(element_obj, inner_path)
            {
                results.extend(values);
            }
        }
        if results.is_empty() {
            None
        } else {
            Some(results)
        }
    })
    .unwrap_or_default()
}

/// Extract string values from a property path, searching inside all values of an object.
///
/// Navigates `object_path` to find an object expression, then for each property value
/// (regardless of key name), navigates `inner_path` to extract string values. Useful for
/// configs with dynamic keys like `angular.json`:
/// - `projects.*.architect.build.options.styles`
#[must_use]
pub fn extract_config_object_nested_string_or_array(
    source: &str,
    path: &Path,
    object_path: &[&str],
    inner_path: &[&str],
) -> Vec<String> {
    extract_config_object_nested(source, path, object_path, |value_obj| {
        get_nested_string_or_array(value_obj, inner_path)
    })
}

/// Extract string values from a property path, searching inside all values of an object.
///
/// Like [`extract_config_object_nested_string_or_array`] but returns a single optional string
/// per object value (useful for fields like `architect.build.options.main`).
#[must_use]
pub fn extract_config_object_nested_strings(
    source: &str,
    path: &Path,
    object_path: &[&str],
    inner_path: &[&str],
) -> Vec<String> {
    extract_config_object_nested(source, path, object_path, |value_obj| {
        get_nested_string_from_object(value_obj, inner_path).map(|s| vec![s])
    })
}

/// Shared helper for object-nested extraction.
///
/// Navigates `object_path` to find an object expression, then for each property value
/// that is itself an object, calls `extract_fn` to produce string values.
fn extract_config_object_nested(
    source: &str,
    path: &Path,
    object_path: &[&str],
    extract_fn: impl Fn(&ObjectExpression<'_>) -> Option<Vec<String>>,
) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        let obj_expr = get_nested_expression(obj, object_path)?;
        let Expression::ObjectExpression(target_obj) = obj_expr else {
            return None;
        };
        let mut results = Vec::new();
        for prop in &target_obj.properties {
            if let ObjectPropertyKind::ObjectProperty(p) = prop
                && let Expression::ObjectExpression(value_obj) = &p.value
                && let Some(values) = extract_fn(value_obj)
            {
                results.extend(values);
            }
        }
        if results.is_empty() {
            None
        } else {
            Some(results)
        }
    })
    .unwrap_or_default()
}

/// Extract `require('...')` call argument strings from a property's value.
///
/// Handles direct require calls and arrays containing require calls or tuples:
/// - `plugins: [require('autoprefixer')]`
/// - `plugins: [require('postcss-import'), [require('postcss-preset-env'), { ... }]]`
#[must_use]
pub fn extract_config_require_strings(source: &str, path: &Path, key: &str) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        let prop = find_property(obj, key)?;
        Some(collect_require_sources(&prop.value))
    })
    .unwrap_or_default()
}

/// Extract alias mappings from an object or array-based alias config.
///
/// Supports common bundler config shapes like:
/// - `resolve.alias = { "@": "./src" }`
/// - `resolve.alias = [{ find: "@", replacement: "./src" }]`
/// - `resolve.alias = [{ find: "@", replacement: fileURLToPath(new URL("./src", import.meta.url)) }]`
#[must_use]
pub fn extract_config_aliases(
    source: &str,
    path: &Path,
    prop_path: &[&str],
) -> Vec<(String, String)> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        let expr = get_nested_expression(obj, prop_path)?;
        let aliases = expression_to_alias_pairs(expr);
        (!aliases.is_empty()).then_some(aliases)
    })
    .unwrap_or_default()
}

/// Extract string values from a nested array, supporting both string elements and
/// object elements with a named string/path field.
///
/// Useful for configs like:
/// - `components: ["~/components", { path: "~/feature-components" }]`
#[must_use]
pub fn extract_config_array_object_strings(
    source: &str,
    path: &Path,
    array_path: &[&str],
    key: &str,
) -> Vec<String> {
    extract_from_source(source, path, |program| {
        let obj = find_config_object(program)?;
        let array_expr = get_nested_expression(obj, array_path)?;
        let Expression::ArrayExpression(arr) = array_expr else {
            return None;
        };

        let mut results = Vec::new();
        for element in &arr.elements {
            let Some(expr) = element.as_expression() else {
                continue;
            };
            match expr {
                Expression::ObjectExpression(item) => {
                    if let Some(prop) = find_property(item, key)
                        && let Some(value) = expression_to_path_string(&prop.value)
                    {
                        results.push(value);
                    }
                }
                _ => {
                    if let Some(value) = expression_to_path_string(expr) {
                        results.push(value);
                    }
                }
            }
        }

        (!results.is_empty()).then_some(results)
    })
    .unwrap_or_default()
}

/// Normalize a config-relative path string to a project-root-relative path.
///
/// Handles values extracted from config files such as `"./src"`, `"src/lib"`,
/// `"/src"`, or absolute filesystem paths under `root`.
#[must_use]
pub fn normalize_config_path(raw: &str, config_path: &Path, root: &Path) -> Option<String> {
    if raw.is_empty() {
        return None;
    }

    let candidate = if let Some(stripped) = raw.strip_prefix('/') {
        lexical_normalize(&root.join(stripped))
    } else {
        let path = Path::new(raw);
        if path.is_absolute() {
            lexical_normalize(path)
        } else {
            let base = config_path.parent().unwrap_or(root);
            lexical_normalize(&base.join(path))
        }
    };

    let relative = candidate.strip_prefix(root).ok()?;
    let normalized = relative.to_string_lossy().replace('\\', "/");
    (!normalized.is_empty()).then_some(normalized)
}

// ── Internal helpers ──────────────────────────────────────────────

/// Parse source and run an extraction function on the AST.
///
/// JSON files (`.json`, `.jsonc`) are parsed as JavaScript expressions wrapped in
/// parentheses to produce an AST compatible with `find_config_object`. The native
/// JSON source type in Oxc produces a different AST structure that our helpers
/// don't handle.
fn extract_from_source<T>(
    source: &str,
    path: &Path,
    extractor: impl FnOnce(&Program) -> Option<T>,
) -> Option<T> {
    let source_type = SourceType::from_path(path).unwrap_or_default();
    let alloc = Allocator::default();

    // For JSON files, wrap in parens and parse as JS so the AST matches
    // what find_config_object expects (ExpressionStatement → ObjectExpression).
    let is_json = path
        .extension()
        .is_some_and(|ext| ext == "json" || ext == "jsonc");
    if is_json {
        let wrapped = format!("({source})");
        let parsed = Parser::new(&alloc, &wrapped, SourceType::mjs()).parse();
        return extractor(&parsed.program);
    }

    let parsed = Parser::new(&alloc, source, source_type).parse();
    extractor(&parsed.program)
}

/// Find the "config object" — the object expression in the default export or module.exports.
///
/// Handles these patterns:
/// - `export default { ... }`
/// - `export default defineConfig({ ... })`
/// - `export default defineConfig(async () => ({ ... }))`
/// - `export default { ... } satisfies Config` / `export default { ... } as Config`
/// - `const config = { ... }; export default config;`
/// - `const config: Config = { ... }; export default config;`
/// - `module.exports = { ... }`
/// - Top-level JSON object (for .json files)
fn find_config_object<'a>(program: &'a Program) -> Option<&'a ObjectExpression<'a>> {
    for stmt in &program.body {
        match stmt {
            // export default { ... } or export default defineConfig({ ... })
            Statement::ExportDefaultDeclaration(decl) => {
                // ExportDefaultDeclarationKind inherits Expression variants directly
                let expr: Option<&Expression> = match &decl.declaration {
                    ExportDefaultDeclarationKind::ObjectExpression(obj) => {
                        return Some(obj);
                    }
                    _ => decl.declaration.as_expression(),
                };
                if let Some(expr) = expr {
                    // Try direct extraction (handles defineConfig(), parens, TS annotations)
                    if let Some(obj) = extract_object_from_expression(expr) {
                        return Some(obj);
                    }
                    // Fallback: resolve identifier reference to variable declaration
                    // Handles: const config: Type = { ... }; export default config;
                    if let Some(name) = unwrap_to_identifier_name(expr) {
                        return find_variable_init_object(program, name);
                    }
                }
            }
            // module.exports = { ... }
            Statement::ExpressionStatement(expr_stmt) => {
                if let Expression::AssignmentExpression(assign) = &expr_stmt.expression
                    && is_module_exports_target(&assign.left)
                {
                    return extract_object_from_expression(&assign.right);
                }
            }
            _ => {}
        }
    }

    // JSON files: the program body might be a single expression statement
    // Also handles JSON wrapped in parens: `({ ... })` (used for tsconfig.json parsing)
    if program.body.len() == 1
        && let Statement::ExpressionStatement(expr_stmt) = &program.body[0]
    {
        match &expr_stmt.expression {
            Expression::ObjectExpression(obj) => return Some(obj),
            Expression::ParenthesizedExpression(paren) => {
                if let Expression::ObjectExpression(obj) = &paren.expression {
                    return Some(obj);
                }
            }
            _ => {}
        }
    }

    None
}

/// Extract an `ObjectExpression` from an expression, handling wrapper patterns.
fn extract_object_from_expression<'a>(
    expr: &'a Expression<'a>,
) -> Option<&'a ObjectExpression<'a>> {
    match expr {
        // Direct object: `{ ... }`
        Expression::ObjectExpression(obj) => Some(obj),
        // Factory call: `defineConfig({ ... })`
        Expression::CallExpression(call) => {
            // Look for the first object argument
            for arg in &call.arguments {
                match arg {
                    Argument::ObjectExpression(obj) => return Some(obj),
                    // Arrow function body: `defineConfig(() => ({ ... }))`
                    Argument::ArrowFunctionExpression(arrow) => {
                        if arrow.expression
                            && !arrow.body.statements.is_empty()
                            && let Statement::ExpressionStatement(expr_stmt) =
                                &arrow.body.statements[0]
                        {
                            return extract_object_from_expression(&expr_stmt.expression);
                        }
                    }
                    _ => {}
                }
            }
            None
        }
        // Parenthesized: `({ ... })`
        Expression::ParenthesizedExpression(paren) => {
            extract_object_from_expression(&paren.expression)
        }
        // TS type annotations: `{ ... } satisfies Config` or `{ ... } as Config`
        Expression::TSSatisfiesExpression(ts_sat) => {
            extract_object_from_expression(&ts_sat.expression)
        }
        Expression::TSAsExpression(ts_as) => extract_object_from_expression(&ts_as.expression),
        _ => None,
    }
}

/// Check if an assignment target is `module.exports`.
fn is_module_exports_target(target: &AssignmentTarget) -> bool {
    if let AssignmentTarget::StaticMemberExpression(member) = target
        && let Expression::Identifier(obj) = &member.object
    {
        return obj.name == "module" && member.property.name == "exports";
    }
    false
}

/// Unwrap TS annotations and return the identifier name if the expression resolves to one.
///
/// Handles `config`, `config satisfies Type`, `config as Type`.
fn unwrap_to_identifier_name<'a>(expr: &'a Expression<'a>) -> Option<&'a str> {
    match expr {
        Expression::Identifier(id) => Some(&id.name),
        Expression::TSSatisfiesExpression(ts_sat) => unwrap_to_identifier_name(&ts_sat.expression),
        Expression::TSAsExpression(ts_as) => unwrap_to_identifier_name(&ts_as.expression),
        _ => None,
    }
}

/// Find a top-level variable declaration by name and extract its init as an object expression.
///
/// Handles `const config = { ... }`, `const config: Type = { ... }`,
/// and `const config = defineConfig({ ... })`.
fn find_variable_init_object<'a>(
    program: &'a Program,
    name: &str,
) -> Option<&'a ObjectExpression<'a>> {
    for stmt in &program.body {
        if let Statement::VariableDeclaration(decl) = stmt {
            for declarator in &decl.declarations {
                if let BindingPattern::BindingIdentifier(id) = &declarator.id
                    && id.name == name
                    && let Some(init) = &declarator.init
                {
                    return extract_object_from_expression(init);
                }
            }
        }
    }
    None
}

/// Find a named property in an object expression.
fn find_property<'a>(obj: &'a ObjectExpression<'a>, key: &str) -> Option<&'a ObjectProperty<'a>> {
    for prop in &obj.properties {
        if let ObjectPropertyKind::ObjectProperty(p) = prop
            && property_key_matches(&p.key, key)
        {
            return Some(p);
        }
    }
    None
}

/// Check if a property key matches a string.
fn property_key_matches(key: &PropertyKey, name: &str) -> bool {
    match key {
        PropertyKey::StaticIdentifier(id) => id.name == name,
        PropertyKey::StringLiteral(s) => s.value == name,
        _ => false,
    }
}

/// Get a string value from an object property.
fn get_object_string_property(obj: &ObjectExpression, key: &str) -> Option<String> {
    find_property(obj, key).and_then(|p| expression_to_string(&p.value))
}

/// Get an array of strings from an object property.
fn get_object_string_array_property(obj: &ObjectExpression, key: &str) -> Vec<String> {
    find_property(obj, key)
        .map(|p| expression_to_string_array(&p.value))
        .unwrap_or_default()
}

/// Navigate a nested property path and get a string array.
fn get_nested_string_array_from_object(
    obj: &ObjectExpression,
    path: &[&str],
) -> Option<Vec<String>> {
    if path.is_empty() {
        return None;
    }
    if path.len() == 1 {
        return Some(get_object_string_array_property(obj, path[0]));
    }
    // Navigate into nested object
    let prop = find_property(obj, path[0])?;
    if let Expression::ObjectExpression(nested) = &prop.value {
        get_nested_string_array_from_object(nested, &path[1..])
    } else {
        None
    }
}

/// Navigate a nested property path and get a string value.
fn get_nested_string_from_object(obj: &ObjectExpression, path: &[&str]) -> Option<String> {
    if path.is_empty() {
        return None;
    }
    if path.len() == 1 {
        return get_object_string_property(obj, path[0]);
    }
    let prop = find_property(obj, path[0])?;
    if let Expression::ObjectExpression(nested) = &prop.value {
        get_nested_string_from_object(nested, &path[1..])
    } else {
        None
    }
}

/// Convert an expression to a string if it's a string literal.
fn expression_to_string(expr: &Expression) -> Option<String> {
    match expr {
        Expression::StringLiteral(s) => Some(s.value.to_string()),
        Expression::TemplateLiteral(t) if t.expressions.is_empty() => {
            // Template literal with no expressions: `\`value\``
            t.quasis.first().map(|q| q.value.raw.to_string())
        }
        _ => None,
    }
}

/// Convert an expression to a path-like string if it's statically recoverable.
fn expression_to_path_string(expr: &Expression) -> Option<String> {
    match expr {
        Expression::ParenthesizedExpression(paren) => expression_to_path_string(&paren.expression),
        Expression::TSAsExpression(ts_as) => expression_to_path_string(&ts_as.expression),
        Expression::TSSatisfiesExpression(ts_sat) => expression_to_path_string(&ts_sat.expression),
        Expression::CallExpression(call) => call_expression_to_path_string(call),
        Expression::NewExpression(new_expr) => new_expression_to_path_string(new_expr),
        _ => expression_to_string(expr),
    }
}

fn call_expression_to_path_string(call: &CallExpression) -> Option<String> {
    if matches!(&call.callee, Expression::Identifier(id) if id.name == "fileURLToPath") {
        return call
            .arguments
            .first()
            .and_then(Argument::as_expression)
            .and_then(expression_to_path_string);
    }

    let callee_name = match &call.callee {
        Expression::Identifier(id) => Some(id.name.as_str()),
        Expression::StaticMemberExpression(member) => Some(member.property.name.as_str()),
        _ => None,
    }?;

    if !matches!(callee_name, "resolve" | "join") {
        return None;
    }

    let mut segments = Vec::new();
    for (index, arg) in call.arguments.iter().enumerate() {
        let expr = arg.as_expression()?;

        if matches!(expr, Expression::Identifier(id) if id.name == "__dirname") {
            if index == 0 {
                continue;
            }
            return None;
        }

        segments.push(expression_to_string(expr)?);
    }

    (!segments.is_empty()).then(|| join_path_segments(&segments))
}

fn new_expression_to_path_string(new_expr: &NewExpression) -> Option<String> {
    if !matches!(&new_expr.callee, Expression::Identifier(id) if id.name == "URL") {
        return None;
    }

    let source = new_expr
        .arguments
        .first()
        .and_then(Argument::as_expression)
        .and_then(expression_to_string)?;

    let base = new_expr
        .arguments
        .get(1)
        .and_then(Argument::as_expression)?;
    is_import_meta_url_expression(base).then_some(source)
}

fn is_import_meta_url_expression(expr: &Expression) -> bool {
    if let Expression::StaticMemberExpression(member) = expr {
        member.property.name == "url" && matches!(member.object, Expression::MetaProperty(_))
    } else {
        false
    }
}

fn join_path_segments(segments: &[String]) -> String {
    let mut joined = PathBuf::new();
    for segment in segments {
        joined.push(segment);
    }
    joined.to_string_lossy().replace('\\', "/")
}

fn expression_to_alias_pairs(expr: &Expression) -> Vec<(String, String)> {
    match expr {
        Expression::ObjectExpression(obj) => obj
            .properties
            .iter()
            .filter_map(|prop| {
                let ObjectPropertyKind::ObjectProperty(prop) = prop else {
                    return None;
                };
                let find = property_key_to_string(&prop.key)?;
                let replacement = expression_to_path_string(&prop.value)?;
                Some((find, replacement))
            })
            .collect(),
        Expression::ArrayExpression(arr) => arr
            .elements
            .iter()
            .filter_map(|element| {
                let Expression::ObjectExpression(obj) = element.as_expression()? else {
                    return None;
                };
                let find = find_property(obj, "find")
                    .and_then(|prop| expression_to_string(&prop.value))?;
                let replacement = find_property(obj, "replacement")
                    .and_then(|prop| expression_to_path_string(&prop.value))?;
                Some((find, replacement))
            })
            .collect(),
        _ => Vec::new(),
    }
}

fn lexical_normalize(path: &Path) -> PathBuf {
    let mut normalized = PathBuf::new();

    for component in path.components() {
        match component {
            std::path::Component::CurDir => {}
            std::path::Component::ParentDir => {
                normalized.pop();
            }
            _ => normalized.push(component.as_os_str()),
        }
    }

    normalized
}

/// Convert an expression to a string array if it's an array of string literals.
fn expression_to_string_array(expr: &Expression) -> Vec<String> {
    match expr {
        Expression::ArrayExpression(arr) => arr
            .elements
            .iter()
            .filter_map(|el| match el {
                ArrayExpressionElement::SpreadElement(_) => None,
                _ => el.as_expression().and_then(expression_to_string),
            })
            .collect(),
        _ => vec![],
    }
}

/// Collect only top-level string values from an expression.
///
/// For arrays, extracts direct string elements and the first string element of sub-arrays
/// (to handle `["pkg-name", { options }]` tuples). Does NOT recurse into objects.
fn collect_shallow_string_values(expr: &Expression) -> Vec<String> {
    let mut values = Vec::new();
    match expr {
        Expression::StringLiteral(s) => {
            values.push(s.value.to_string());
        }
        Expression::ArrayExpression(arr) => {
            for el in &arr.elements {
                if let Some(inner) = el.as_expression() {
                    match inner {
                        Expression::StringLiteral(s) => {
                            values.push(s.value.to_string());
                        }
                        // Handle tuples: ["pkg-name", { options }] → extract first string
                        Expression::ArrayExpression(sub_arr) => {
                            if let Some(first) = sub_arr.elements.first()
                                && let Some(first_expr) = first.as_expression()
                                && let Some(s) = expression_to_string(first_expr)
                            {
                                values.push(s);
                            }
                        }
                        _ => {}
                    }
                }
            }
        }
        // Handle objects: { "key": "value" } or { "key": ["pkg", { opts }] } → extract values
        Expression::ObjectExpression(obj) => {
            for prop in &obj.properties {
                if let ObjectPropertyKind::ObjectProperty(p) = prop {
                    match &p.value {
                        Expression::StringLiteral(s) => {
                            values.push(s.value.to_string());
                        }
                        // Handle tuples: { "key": ["pkg-name", { options }] }
                        Expression::ArrayExpression(sub_arr) => {
                            if let Some(first) = sub_arr.elements.first()
                                && let Some(first_expr) = first.as_expression()
                                && let Some(s) = expression_to_string(first_expr)
                            {
                                values.push(s);
                            }
                        }
                        _ => {}
                    }
                }
            }
        }
        _ => {}
    }
    values
}

/// Recursively collect all string literal values from an expression tree.
fn collect_all_string_values(expr: &Expression, values: &mut Vec<String>) {
    match expr {
        Expression::StringLiteral(s) => {
            values.push(s.value.to_string());
        }
        Expression::ArrayExpression(arr) => {
            for el in &arr.elements {
                if let Some(expr) = el.as_expression() {
                    collect_all_string_values(expr, values);
                }
            }
        }
        Expression::ObjectExpression(obj) => {
            for prop in &obj.properties {
                if let ObjectPropertyKind::ObjectProperty(p) = prop {
                    collect_all_string_values(&p.value, values);
                }
            }
        }
        _ => {}
    }
}

/// Convert a `PropertyKey` to a `String`.
fn property_key_to_string(key: &PropertyKey) -> Option<String> {
    match key {
        PropertyKey::StaticIdentifier(id) => Some(id.name.to_string()),
        PropertyKey::StringLiteral(s) => Some(s.value.to_string()),
        _ => None,
    }
}

/// Extract keys of an object at a nested property path.
fn get_nested_object_keys(obj: &ObjectExpression, path: &[&str]) -> Option<Vec<String>> {
    if path.is_empty() {
        return None;
    }
    let prop = find_property(obj, path[0])?;
    if path.len() == 1 {
        if let Expression::ObjectExpression(nested) = &prop.value {
            let keys = nested
                .properties
                .iter()
                .filter_map(|p| {
                    if let ObjectPropertyKind::ObjectProperty(p) = p {
                        property_key_to_string(&p.key)
                    } else {
                        None
                    }
                })
                .collect();
            return Some(keys);
        }
        return None;
    }
    if let Expression::ObjectExpression(nested) = &prop.value {
        get_nested_object_keys(nested, &path[1..])
    } else {
        None
    }
}

/// Navigate a nested property path and return the raw expression at the end.
fn get_nested_expression<'a>(
    obj: &'a ObjectExpression<'a>,
    path: &[&str],
) -> Option<&'a Expression<'a>> {
    if path.is_empty() {
        return None;
    }
    let prop = find_property(obj, path[0])?;
    if path.len() == 1 {
        return Some(&prop.value);
    }
    if let Expression::ObjectExpression(nested) = &prop.value {
        get_nested_expression(nested, &path[1..])
    } else {
        None
    }
}

/// Navigate a nested path and extract a string, string array, or object string values.
fn get_nested_string_or_array(obj: &ObjectExpression, path: &[&str]) -> Option<Vec<String>> {
    if path.is_empty() {
        return None;
    }
    if path.len() == 1 {
        let prop = find_property(obj, path[0])?;
        return Some(expression_to_string_or_array(&prop.value));
    }
    let prop = find_property(obj, path[0])?;
    if let Expression::ObjectExpression(nested) = &prop.value {
        get_nested_string_or_array(nested, &path[1..])
    } else {
        None
    }
}

/// Convert an expression to a `Vec<String>`, handling string, array, and object-with-string-values.
fn expression_to_string_or_array(expr: &Expression) -> Vec<String> {
    match expr {
        Expression::StringLiteral(s) => vec![s.value.to_string()],
        Expression::TemplateLiteral(t) if t.expressions.is_empty() => t
            .quasis
            .first()
            .map(|q| vec![q.value.raw.to_string()])
            .unwrap_or_default(),
        Expression::ArrayExpression(arr) => arr
            .elements
            .iter()
            .filter_map(|el| el.as_expression().and_then(expression_to_string))
            .collect(),
        Expression::ObjectExpression(obj) => obj
            .properties
            .iter()
            .filter_map(|p| {
                if let ObjectPropertyKind::ObjectProperty(p) = p {
                    expression_to_string(&p.value)
                } else {
                    None
                }
            })
            .collect(),
        _ => vec![],
    }
}

/// Collect `require('...')` argument strings from an expression.
fn collect_require_sources(expr: &Expression) -> Vec<String> {
    let mut sources = Vec::new();
    match expr {
        Expression::CallExpression(call) if is_require_call(call) => {
            if let Some(s) = get_require_source(call) {
                sources.push(s);
            }
        }
        Expression::ArrayExpression(arr) => {
            for el in &arr.elements {
                if let Some(inner) = el.as_expression() {
                    match inner {
                        Expression::CallExpression(call) if is_require_call(call) => {
                            if let Some(s) = get_require_source(call) {
                                sources.push(s);
                            }
                        }
                        // Tuple: [require('pkg'), options]
                        Expression::ArrayExpression(sub_arr) => {
                            if let Some(first) = sub_arr.elements.first()
                                && let Some(Expression::CallExpression(call)) =
                                    first.as_expression()
                                && is_require_call(call)
                                && let Some(s) = get_require_source(call)
                            {
                                sources.push(s);
                            }
                        }
                        _ => {}
                    }
                }
            }
        }
        _ => {}
    }
    sources
}

/// Check if a call expression is `require(...)`.
fn is_require_call(call: &CallExpression) -> bool {
    matches!(&call.callee, Expression::Identifier(id) if id.name == "require")
}

/// Get the first string argument of a `require()` call.
fn get_require_source(call: &CallExpression) -> Option<String> {
    call.arguments.first().and_then(|arg| {
        if let Argument::StringLiteral(s) = arg {
            Some(s.value.to_string())
        } else {
            None
        }
    })
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::path::PathBuf;

    fn js_path() -> PathBuf {
        PathBuf::from("config.js")
    }

    fn ts_path() -> PathBuf {
        PathBuf::from("config.ts")
    }

    #[test]
    fn extract_imports_basic() {
        let source = r"
            import foo from 'foo-pkg';
            import { bar } from '@scope/bar';
            export default {};
        ";
        let imports = extract_imports(source, &js_path());
        assert_eq!(imports, vec!["foo-pkg", "@scope/bar"]);
    }

    #[test]
    fn extract_default_export_object_property() {
        let source = r#"export default { testDir: "./tests" };"#;
        let val = extract_config_string(source, &js_path(), &["testDir"]);
        assert_eq!(val, Some("./tests".to_string()));
    }

    #[test]
    fn extract_define_config_property() {
        let source = r#"
            import { defineConfig } from 'vitest/config';
            export default defineConfig({
                test: {
                    include: ["**/*.test.ts", "**/*.spec.ts"],
                    setupFiles: ["./test/setup.ts"]
                }
            });
        "#;
        let include = extract_config_string_array(source, &ts_path(), &["test", "include"]);
        assert_eq!(include, vec!["**/*.test.ts", "**/*.spec.ts"]);

        let setup = extract_config_string_array(source, &ts_path(), &["test", "setupFiles"]);
        assert_eq!(setup, vec!["./test/setup.ts"]);
    }

    #[test]
    fn extract_module_exports_property() {
        let source = r#"module.exports = { testEnvironment: "jsdom" };"#;
        let val = extract_config_string(source, &js_path(), &["testEnvironment"]);
        assert_eq!(val, Some("jsdom".to_string()));
    }

    #[test]
    fn extract_nested_string_array() {
        let source = r#"
            export default {
                resolve: {
                    alias: {
                        "@": "./src"
                    }
                },
                test: {
                    include: ["src/**/*.test.ts"]
                }
            };
        "#;
        let include = extract_config_string_array(source, &js_path(), &["test", "include"]);
        assert_eq!(include, vec!["src/**/*.test.ts"]);
    }

    #[test]
    fn extract_addons_array() {
        let source = r#"
            export default {
                addons: [
                    "@storybook/addon-a11y",
                    "@storybook/addon-docs",
                    "@storybook/addon-links"
                ]
            };
        "#;
        let addons = extract_config_property_strings(source, &ts_path(), "addons");
        assert_eq!(
            addons,
            vec![
                "@storybook/addon-a11y",
                "@storybook/addon-docs",
                "@storybook/addon-links"
            ]
        );
    }

    #[test]
    fn handle_empty_config() {
        let source = "";
        let result = extract_config_string(source, &js_path(), &["key"]);
        assert_eq!(result, None);
    }

    // ── extract_config_object_keys tests ────────────────────────────

    #[test]
    fn object_keys_postcss_plugins() {
        let source = r"
            module.exports = {
                plugins: {
                    autoprefixer: {},
                    tailwindcss: {},
                    'postcss-import': {}
                }
            };
        ";
        let keys = extract_config_object_keys(source, &js_path(), &["plugins"]);
        assert_eq!(keys, vec!["autoprefixer", "tailwindcss", "postcss-import"]);
    }

    #[test]
    fn object_keys_nested_path() {
        let source = r"
            export default {
                build: {
                    plugins: {
                        minify: {},
                        compress: {}
                    }
                }
            };
        ";
        let keys = extract_config_object_keys(source, &js_path(), &["build", "plugins"]);
        assert_eq!(keys, vec!["minify", "compress"]);
    }

    #[test]
    fn object_keys_empty_object() {
        let source = r"export default { plugins: {} };";
        let keys = extract_config_object_keys(source, &js_path(), &["plugins"]);
        assert!(keys.is_empty());
    }

    #[test]
    fn object_keys_non_object_returns_empty() {
        let source = r#"export default { plugins: ["a", "b"] };"#;
        let keys = extract_config_object_keys(source, &js_path(), &["plugins"]);
        assert!(keys.is_empty());
    }

    // ── extract_config_string_or_array tests ────────────────────────

    #[test]
    fn string_or_array_single_string() {
        let source = r#"export default { entry: "./src/index.js" };"#;
        let result = extract_config_string_or_array(source, &js_path(), &["entry"]);
        assert_eq!(result, vec!["./src/index.js"]);
    }

    #[test]
    fn string_or_array_array() {
        let source = r#"export default { entry: ["./src/a.js", "./src/b.js"] };"#;
        let result = extract_config_string_or_array(source, &js_path(), &["entry"]);
        assert_eq!(result, vec!["./src/a.js", "./src/b.js"]);
    }

    #[test]
    fn string_or_array_object_values() {
        let source =
            r#"export default { entry: { main: "./src/main.js", vendor: "./src/vendor.js" } };"#;
        let result = extract_config_string_or_array(source, &js_path(), &["entry"]);
        assert_eq!(result, vec!["./src/main.js", "./src/vendor.js"]);
    }

    #[test]
    fn string_or_array_nested_path() {
        let source = r#"
            export default {
                build: {
                    rollupOptions: {
                        input: ["./index.html", "./about.html"]
                    }
                }
            };
        "#;
        let result = extract_config_string_or_array(
            source,
            &js_path(),
            &["build", "rollupOptions", "input"],
        );
        assert_eq!(result, vec!["./index.html", "./about.html"]);
    }

    #[test]
    fn string_or_array_template_literal() {
        let source = r"export default { entry: `./src/index.js` };";
        let result = extract_config_string_or_array(source, &js_path(), &["entry"]);
        assert_eq!(result, vec!["./src/index.js"]);
    }

    // ── extract_config_require_strings tests ────────────────────────

    #[test]
    fn require_strings_array() {
        let source = r"
            module.exports = {
                plugins: [
                    require('autoprefixer'),
                    require('postcss-import')
                ]
            };
        ";
        let deps = extract_config_require_strings(source, &js_path(), "plugins");
        assert_eq!(deps, vec!["autoprefixer", "postcss-import"]);
    }

    #[test]
    fn require_strings_with_tuples() {
        let source = r"
            module.exports = {
                plugins: [
                    require('autoprefixer'),
                    [require('postcss-preset-env'), { stage: 3 }]
                ]
            };
        ";
        let deps = extract_config_require_strings(source, &js_path(), "plugins");
        assert_eq!(deps, vec!["autoprefixer", "postcss-preset-env"]);
    }

    #[test]
    fn require_strings_empty_array() {
        let source = r"module.exports = { plugins: [] };";
        let deps = extract_config_require_strings(source, &js_path(), "plugins");
        assert!(deps.is_empty());
    }

    #[test]
    fn require_strings_no_require_calls() {
        let source = r#"module.exports = { plugins: ["a", "b"] };"#;
        let deps = extract_config_require_strings(source, &js_path(), "plugins");
        assert!(deps.is_empty());
    }

    #[test]
    fn extract_aliases_from_object_with_file_url_to_path() {
        let source = r#"
            import { defineConfig } from 'vite';
            import { fileURLToPath, URL } from 'node:url';

            export default defineConfig({
                resolve: {
                    alias: {
                        "@": fileURLToPath(new URL("./src", import.meta.url))
                    }
                }
            });
        "#;

        let aliases = extract_config_aliases(source, &ts_path(), &["resolve", "alias"]);
        assert_eq!(aliases, vec![("@".to_string(), "./src".to_string())]);
    }

    #[test]
    fn extract_aliases_from_array_form() {
        let source = r#"
            export default {
                resolve: {
                    alias: [
                        { find: "@", replacement: "./src" },
                        { find: "$utils", replacement: "src/lib/utils" }
                    ]
                }
            };
        "#;

        let aliases = extract_config_aliases(source, &ts_path(), &["resolve", "alias"]);
        assert_eq!(
            aliases,
            vec![
                ("@".to_string(), "./src".to_string()),
                ("$utils".to_string(), "src/lib/utils".to_string())
            ]
        );
    }

    #[test]
    fn extract_array_object_strings_mixed_forms() {
        let source = r#"
            export default {
                components: [
                    "~/components",
                    { path: "@/feature-components" }
                ]
            };
        "#;

        let values =
            extract_config_array_object_strings(source, &ts_path(), &["components"], "path");
        assert_eq!(
            values,
            vec![
                "~/components".to_string(),
                "@/feature-components".to_string()
            ]
        );
    }

    #[test]
    fn normalize_config_path_relative_to_root() {
        let config_path = PathBuf::from("/project/vite.config.ts");
        let root = PathBuf::from("/project");

        assert_eq!(
            normalize_config_path("./src/lib", &config_path, &root),
            Some("src/lib".to_string())
        );
        assert_eq!(
            normalize_config_path("/src/lib", &config_path, &root),
            Some("src/lib".to_string())
        );
    }

    // ── JSON wrapped in parens (for tsconfig.json parsing) ──────────

    #[test]
    fn json_wrapped_in_parens_string() {
        let source = r#"({"extends": "@tsconfig/node18/tsconfig.json"})"#;
        let val = extract_config_string(source, &js_path(), &["extends"]);
        assert_eq!(val, Some("@tsconfig/node18/tsconfig.json".to_string()));
    }

    #[test]
    fn json_wrapped_in_parens_nested_array() {
        let source =
            r#"({"compilerOptions": {"types": ["node", "jest"]}, "include": ["src/**/*"]})"#;
        let types = extract_config_string_array(source, &js_path(), &["compilerOptions", "types"]);
        assert_eq!(types, vec!["node", "jest"]);

        let include = extract_config_string_array(source, &js_path(), &["include"]);
        assert_eq!(include, vec!["src/**/*"]);
    }

    #[test]
    fn json_wrapped_in_parens_object_keys() {
        let source = r#"({"plugins": {"autoprefixer": {}, "tailwindcss": {}}})"#;
        let keys = extract_config_object_keys(source, &js_path(), &["plugins"]);
        assert_eq!(keys, vec!["autoprefixer", "tailwindcss"]);
    }

    // ── JSON file extension detection ────────────────────────────

    fn json_path() -> PathBuf {
        PathBuf::from("config.json")
    }

    #[test]
    fn json_file_parsed_correctly() {
        let source = r#"{"key": "value", "list": ["a", "b"]}"#;
        let val = extract_config_string(source, &json_path(), &["key"]);
        assert_eq!(val, Some("value".to_string()));

        let list = extract_config_string_array(source, &json_path(), &["list"]);
        assert_eq!(list, vec!["a", "b"]);
    }

    #[test]
    fn jsonc_file_parsed_correctly() {
        let source = r#"{"key": "value"}"#;
        let path = PathBuf::from("tsconfig.jsonc");
        let val = extract_config_string(source, &path, &["key"]);
        assert_eq!(val, Some("value".to_string()));
    }

    // ── defineConfig with arrow function ─────────────────────────

    #[test]
    fn extract_define_config_arrow_function() {
        let source = r#"
            import { defineConfig } from 'vite';
            export default defineConfig(() => ({
                test: {
                    include: ["**/*.test.ts"]
                }
            }));
        "#;
        let include = extract_config_string_array(source, &ts_path(), &["test", "include"]);
        assert_eq!(include, vec!["**/*.test.ts"]);
    }

    // ── module.exports with nested properties ────────────────────

    #[test]
    fn module_exports_nested_string() {
        let source = r#"
            module.exports = {
                resolve: {
                    alias: {
                        "@": "./src"
                    }
                }
            };
        "#;
        let val = extract_config_string(source, &js_path(), &["resolve", "alias", "@"]);
        assert_eq!(val, Some("./src".to_string()));
    }

    // ── extract_config_property_strings (recursive) ──────────────

    #[test]
    fn property_strings_nested_objects() {
        let source = r#"
            export default {
                plugins: {
                    group1: { a: "val-a" },
                    group2: { b: "val-b" }
                }
            };
        "#;
        let values = extract_config_property_strings(source, &js_path(), "plugins");
        assert!(values.contains(&"val-a".to_string()));
        assert!(values.contains(&"val-b".to_string()));
    }

    #[test]
    fn property_strings_missing_key_returns_empty() {
        let source = r#"export default { other: "value" };"#;
        let values = extract_config_property_strings(source, &js_path(), "missing");
        assert!(values.is_empty());
    }

    // ── extract_config_shallow_strings ────────────────────────────

    #[test]
    fn shallow_strings_tuple_array() {
        let source = r#"
            module.exports = {
                reporters: ["default", ["jest-junit", { outputDirectory: "reports" }]]
            };
        "#;
        let values = extract_config_shallow_strings(source, &js_path(), "reporters");
        assert_eq!(values, vec!["default", "jest-junit"]);
        // "reports" should NOT be extracted (it's inside an options object)
        assert!(!values.contains(&"reports".to_string()));
    }

    #[test]
    fn shallow_strings_single_string() {
        let source = r#"export default { preset: "ts-jest" };"#;
        let values = extract_config_shallow_strings(source, &js_path(), "preset");
        assert_eq!(values, vec!["ts-jest"]);
    }

    #[test]
    fn shallow_strings_missing_key() {
        let source = r#"export default { other: "val" };"#;
        let values = extract_config_shallow_strings(source, &js_path(), "missing");
        assert!(values.is_empty());
    }

    // ── extract_config_nested_shallow_strings tests ──────────────

    #[test]
    fn nested_shallow_strings_vitest_reporters() {
        let source = r#"
            export default {
                test: {
                    reporters: ["default", "vitest-sonar-reporter"]
                }
            };
        "#;
        let values =
            extract_config_nested_shallow_strings(source, &js_path(), &["test"], "reporters");
        assert_eq!(values, vec!["default", "vitest-sonar-reporter"]);
    }

    #[test]
    fn nested_shallow_strings_tuple_format() {
        let source = r#"
            export default {
                test: {
                    reporters: ["default", ["vitest-sonar-reporter", { outputFile: "report.xml" }]]
                }
            };
        "#;
        let values =
            extract_config_nested_shallow_strings(source, &js_path(), &["test"], "reporters");
        assert_eq!(values, vec!["default", "vitest-sonar-reporter"]);
    }

    #[test]
    fn nested_shallow_strings_missing_outer() {
        let source = r"export default { other: {} };";
        let values =
            extract_config_nested_shallow_strings(source, &js_path(), &["test"], "reporters");
        assert!(values.is_empty());
    }

    #[test]
    fn nested_shallow_strings_missing_inner() {
        let source = r#"export default { test: { include: ["**/*.test.ts"] } };"#;
        let values =
            extract_config_nested_shallow_strings(source, &js_path(), &["test"], "reporters");
        assert!(values.is_empty());
    }

    // ── extract_config_string_or_array edge cases ────────────────

    #[test]
    fn string_or_array_missing_path() {
        let source = r"export default {};";
        let result = extract_config_string_or_array(source, &js_path(), &["entry"]);
        assert!(result.is_empty());
    }

    #[test]
    fn string_or_array_non_string_values() {
        // When values are not strings (e.g., numbers), they should be skipped
        let source = r"export default { entry: [42, true] };";
        let result = extract_config_string_or_array(source, &js_path(), &["entry"]);
        assert!(result.is_empty());
    }

    // ── extract_config_array_nested_string_or_array ──────────────

    #[test]
    fn array_nested_extraction() {
        let source = r#"
            export default defineConfig({
                test: {
                    projects: [
                        {
                            test: {
                                setupFiles: ["./test/setup-a.ts"]
                            }
                        },
                        {
                            test: {
                                setupFiles: "./test/setup-b.ts"
                            }
                        }
                    ]
                }
            });
        "#;
        let results = extract_config_array_nested_string_or_array(
            source,
            &ts_path(),
            &["test", "projects"],
            &["test", "setupFiles"],
        );
        assert!(results.contains(&"./test/setup-a.ts".to_string()));
        assert!(results.contains(&"./test/setup-b.ts".to_string()));
    }

    #[test]
    fn array_nested_empty_when_no_array() {
        let source = r#"export default { test: { projects: "not-an-array" } };"#;
        let results = extract_config_array_nested_string_or_array(
            source,
            &js_path(),
            &["test", "projects"],
            &["test", "setupFiles"],
        );
        assert!(results.is_empty());
    }

    // ── extract_config_object_nested_string_or_array ─────────────

    #[test]
    fn object_nested_extraction() {
        let source = r#"{
            "projects": {
                "app-one": {
                    "architect": {
                        "build": {
                            "options": {
                                "styles": ["src/styles.css"]
                            }
                        }
                    }
                }
            }
        }"#;
        let results = extract_config_object_nested_string_or_array(
            source,
            &json_path(),
            &["projects"],
            &["architect", "build", "options", "styles"],
        );
        assert_eq!(results, vec!["src/styles.css"]);
    }

    // ── extract_config_object_nested_strings ─────────────────────

    #[test]
    fn object_nested_strings_extraction() {
        let source = r#"{
            "targets": {
                "build": {
                    "executor": "@angular/build:application"
                },
                "test": {
                    "executor": "@nx/vite:test"
                }
            }
        }"#;
        let results =
            extract_config_object_nested_strings(source, &json_path(), &["targets"], &["executor"]);
        assert!(results.contains(&"@angular/build:application".to_string()));
        assert!(results.contains(&"@nx/vite:test".to_string()));
    }

    // ── extract_config_require_strings edge cases ────────────────

    #[test]
    fn require_strings_direct_call() {
        let source = r"module.exports = { adapter: require('@sveltejs/adapter-node') };";
        let deps = extract_config_require_strings(source, &js_path(), "adapter");
        assert_eq!(deps, vec!["@sveltejs/adapter-node"]);
    }

    #[test]
    fn require_strings_no_matching_key() {
        let source = r"module.exports = { other: require('something') };";
        let deps = extract_config_require_strings(source, &js_path(), "plugins");
        assert!(deps.is_empty());
    }

    // ── extract_imports edge cases ───────────────────────────────

    #[test]
    fn extract_imports_no_imports() {
        let source = r"export default {};";
        let imports = extract_imports(source, &js_path());
        assert!(imports.is_empty());
    }

    #[test]
    fn extract_imports_side_effect_import() {
        let source = r"
            import 'polyfill';
            import './local-setup';
            export default {};
        ";
        let imports = extract_imports(source, &js_path());
        assert_eq!(imports, vec!["polyfill", "./local-setup"]);
    }

    #[test]
    fn extract_imports_mixed_specifiers() {
        let source = r"
            import defaultExport from 'module-a';
            import { named } from 'module-b';
            import * as ns from 'module-c';
            export default {};
        ";
        let imports = extract_imports(source, &js_path());
        assert_eq!(imports, vec!["module-a", "module-b", "module-c"]);
    }

    // ── Template literal support ─────────────────────────────────

    #[test]
    fn template_literal_in_string_or_array() {
        let source = r"export default { entry: `./src/index.ts` };";
        let result = extract_config_string_or_array(source, &ts_path(), &["entry"]);
        assert_eq!(result, vec!["./src/index.ts"]);
    }

    #[test]
    fn template_literal_in_config_string() {
        let source = r"export default { testDir: `./tests` };";
        let val = extract_config_string(source, &js_path(), &["testDir"]);
        assert_eq!(val, Some("./tests".to_string()));
    }

    // ── Empty/missing path navigation ────────────────────────────

    #[test]
    fn nested_string_array_empty_path() {
        let source = r#"export default { items: ["a", "b"] };"#;
        let result = extract_config_string_array(source, &js_path(), &[]);
        assert!(result.is_empty());
    }

    #[test]
    fn nested_string_empty_path() {
        let source = r#"export default { key: "val" };"#;
        let result = extract_config_string(source, &js_path(), &[]);
        assert!(result.is_none());
    }

    #[test]
    fn object_keys_empty_path() {
        let source = r"export default { plugins: {} };";
        let result = extract_config_object_keys(source, &js_path(), &[]);
        assert!(result.is_empty());
    }

    // ── No config object found ───────────────────────────────────

    #[test]
    fn no_config_object_returns_empty() {
        // Source with no default export or module.exports
        let source = r"const x = 42;";
        let result = extract_config_string(source, &js_path(), &["key"]);
        assert!(result.is_none());

        let arr = extract_config_string_array(source, &js_path(), &["items"]);
        assert!(arr.is_empty());

        let keys = extract_config_object_keys(source, &js_path(), &["plugins"]);
        assert!(keys.is_empty());
    }

    // ── String literal with string key property ──────────────────

    #[test]
    fn property_with_string_key() {
        let source = r#"export default { "string-key": "value" };"#;
        let val = extract_config_string(source, &js_path(), &["string-key"]);
        assert_eq!(val, Some("value".to_string()));
    }

    #[test]
    fn nested_navigation_through_non_object() {
        // Trying to navigate through a string value should return None
        let source = r#"export default { level1: "not-an-object" };"#;
        let val = extract_config_string(source, &js_path(), &["level1", "level2"]);
        assert!(val.is_none());
    }

    // ── Variable reference resolution ───────────────────────────

    #[test]
    fn variable_reference_untyped() {
        let source = r#"
            const config = {
                testDir: "./tests"
            };
            export default config;
        "#;
        let val = extract_config_string(source, &js_path(), &["testDir"]);
        assert_eq!(val, Some("./tests".to_string()));
    }

    #[test]
    fn variable_reference_with_type_annotation() {
        let source = r#"
            import type { StorybookConfig } from '@storybook/react-vite';
            const config: StorybookConfig = {
                addons: ["@storybook/addon-a11y", "@storybook/addon-docs"],
                framework: "@storybook/react-vite"
            };
            export default config;
        "#;
        let addons = extract_config_shallow_strings(source, &ts_path(), "addons");
        assert_eq!(
            addons,
            vec!["@storybook/addon-a11y", "@storybook/addon-docs"]
        );

        let framework = extract_config_string(source, &ts_path(), &["framework"]);
        assert_eq!(framework, Some("@storybook/react-vite".to_string()));
    }

    #[test]
    fn variable_reference_with_define_config() {
        let source = r#"
            import { defineConfig } from 'vitest/config';
            const config = defineConfig({
                test: {
                    include: ["**/*.test.ts"]
                }
            });
            export default config;
        "#;
        let include = extract_config_string_array(source, &ts_path(), &["test", "include"]);
        assert_eq!(include, vec!["**/*.test.ts"]);
    }

    // ── TS type annotation wrappers ─────────────────────────────

    #[test]
    fn ts_satisfies_direct_export() {
        let source = r#"
            export default {
                testDir: "./tests"
            } satisfies PlaywrightTestConfig;
        "#;
        let val = extract_config_string(source, &ts_path(), &["testDir"]);
        assert_eq!(val, Some("./tests".to_string()));
    }

    #[test]
    fn ts_as_direct_export() {
        let source = r#"
            export default {
                testDir: "./tests"
            } as const;
        "#;
        let val = extract_config_string(source, &ts_path(), &["testDir"]);
        assert_eq!(val, Some("./tests".to_string()));
    }
}