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nginx_lint_plugin/
types.rs

1//! Core types for plugin development.
2//!
3//! This module provides the fundamental types needed to build nginx-lint plugins:
4//!
5//! - [`Plugin`] - The trait every plugin must implement
6//! - [`PluginSpec`] - Plugin metadata (name, category, description, examples)
7//! - [`LintError`] - Lint errors reported by plugins
8//! - [`ErrorBuilder`] - Helper for creating errors with pre-filled rule/category
9//! - [`Fix`] - Autofix actions (replace, delete, insert)
10//! - [`ConfigExt`] - Extension trait for traversing the nginx config AST
11//! - [`DirectiveExt`] - Extension trait for inspecting and modifying directives
12//! - [`DirectiveWithContext`] - A directive paired with its parent block context
13//!
14//! These types mirror the nginx-lint AST and error types for use in WASM plugins.
15
16use serde::{Deserialize, Serialize};
17
18/// Current API version for the plugin SDK
19pub const API_VERSION: &str = "1.0";
20
21/// Plugin metadata describing a lint rule.
22///
23/// Created via [`PluginSpec::new()`] and configured with builder methods.
24///
25/// # Example
26///
27/// ```
28/// use nginx_lint_plugin::PluginSpec;
29///
30/// let spec = PluginSpec::new("my-rule", "security", "Short description")
31///     .with_severity("warning")
32///     .with_why("Detailed explanation of why this rule exists.")
33///     .with_bad_example("server {\n    bad_directive on;\n}")
34///     .with_good_example("server {\n    bad_directive off;\n}")
35///     .with_references(vec![
36///         "https://nginx.org/en/docs/...".to_string(),
37///     ]);
38///
39/// assert_eq!(spec.name, "my-rule");
40/// assert_eq!(spec.category, "security");
41/// assert_eq!(spec.severity, Some("warning".to_string()));
42/// ```
43#[derive(Debug, Clone, Serialize, Deserialize)]
44pub struct PluginSpec {
45    /// Unique name for the rule (e.g., "my-custom-rule")
46    pub name: String,
47    /// Category (e.g., "security", "style", "best_practices", "custom")
48    pub category: String,
49    /// Human-readable description
50    pub description: String,
51    /// API version the plugin uses for input/output format
52    pub api_version: String,
53    /// Severity level (error, warning)
54    #[serde(default, skip_serializing_if = "Option::is_none")]
55    pub severity: Option<String>,
56    /// Why this rule exists (detailed explanation)
57    #[serde(default, skip_serializing_if = "Option::is_none")]
58    pub why: Option<String>,
59    /// Example of bad configuration
60    #[serde(default, skip_serializing_if = "Option::is_none")]
61    pub bad_example: Option<String>,
62    /// Example of good configuration
63    #[serde(default, skip_serializing_if = "Option::is_none")]
64    pub good_example: Option<String>,
65    /// References (URLs, documentation links)
66    #[serde(default, skip_serializing_if = "Option::is_none")]
67    pub references: Option<Vec<String>>,
68}
69
70impl PluginSpec {
71    /// Create a new PluginSpec with the current API version
72    pub fn new(
73        name: impl Into<String>,
74        category: impl Into<String>,
75        description: impl Into<String>,
76    ) -> Self {
77        Self {
78            name: name.into(),
79            category: category.into(),
80            description: description.into(),
81            api_version: API_VERSION.to_string(),
82            severity: None,
83            why: None,
84            bad_example: None,
85            good_example: None,
86            references: None,
87        }
88    }
89
90    /// Set the severity level
91    pub fn with_severity(mut self, severity: impl Into<String>) -> Self {
92        self.severity = Some(severity.into());
93        self
94    }
95
96    /// Set the why documentation
97    pub fn with_why(mut self, why: impl Into<String>) -> Self {
98        self.why = Some(why.into());
99        self
100    }
101
102    /// Set the bad example
103    pub fn with_bad_example(mut self, example: impl Into<String>) -> Self {
104        self.bad_example = Some(example.into());
105        self
106    }
107
108    /// Set the good example
109    pub fn with_good_example(mut self, example: impl Into<String>) -> Self {
110        self.good_example = Some(example.into());
111        self
112    }
113
114    /// Set references
115    pub fn with_references(mut self, refs: Vec<String>) -> Self {
116        self.references = Some(refs);
117        self
118    }
119
120    /// Create an error builder that uses this plugin's name and category
121    ///
122    /// This reduces boilerplate when creating errors in the check method.
123    ///
124    /// # Example
125    ///
126    /// ```
127    /// use nginx_lint_plugin::{PluginSpec, Severity};
128    ///
129    /// let spec = PluginSpec::new("my-rule", "security", "Check something");
130    /// let err = spec.error_builder();
131    ///
132    /// // Instead of:
133    /// //   LintError::warning("my-rule", "security", "message", 10, 5)
134    /// // Use:
135    /// let warning = err.warning("message", 10, 5);
136    /// assert_eq!(warning.rule, "my-rule");
137    /// assert_eq!(warning.category, "security");
138    /// assert_eq!(warning.severity, Severity::Warning);
139    /// ```
140    pub fn error_builder(&self) -> ErrorBuilder {
141        ErrorBuilder {
142            rule: self.name.clone(),
143            category: self.category.clone(),
144        }
145    }
146}
147
148/// Builder for creating LintError with pre-filled rule and category
149#[derive(Debug, Clone)]
150pub struct ErrorBuilder {
151    rule: String,
152    category: String,
153}
154
155impl ErrorBuilder {
156    /// Create an error with Error severity
157    pub fn error(&self, message: &str, line: usize, column: usize) -> LintError {
158        LintError::error(&self.rule, &self.category, message, line, column)
159    }
160
161    /// Create an error with Warning severity
162    pub fn warning(&self, message: &str, line: usize, column: usize) -> LintError {
163        LintError::warning(&self.rule, &self.category, message, line, column)
164    }
165
166    /// Create an error from a directive's location
167    pub fn error_at(&self, message: &str, directive: &Directive) -> LintError {
168        self.error(
169            message,
170            directive.span.start.line,
171            directive.span.start.column,
172        )
173    }
174
175    /// Create a warning from a directive's location
176    pub fn warning_at(&self, message: &str, directive: &Directive) -> LintError {
177        self.warning(
178            message,
179            directive.span.start.line,
180            directive.span.start.column,
181        )
182    }
183}
184
185/// Severity level for lint errors
186#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
187#[serde(rename_all = "lowercase")]
188pub enum Severity {
189    Error,
190    Warning,
191}
192
193/// Represents a fix that can be applied to automatically resolve a lint error.
194///
195/// Fixes can operate in two modes:
196///
197/// - **Line-based**: Operate on entire lines (delete, insert after, replace text on a line)
198/// - **Range-based**: Operate on byte offsets for precise edits (multiple fixes per line)
199///
200/// Use the convenience methods on [`DirectiveExt`] to create fixes from directives:
201///
202/// ```
203/// use nginx_lint_plugin::prelude::*;
204///
205/// let config = nginx_lint_plugin::parse_string("server_tokens on;").unwrap();
206/// let directive = config.all_directives().next().unwrap();
207///
208/// // Replace the entire directive
209/// let fix = directive.replace_with("server_tokens off;");
210/// assert!(fix.is_range_based());
211///
212/// // Delete the directive's line
213/// let fix = directive.delete_line();
214/// assert!(fix.delete_line);
215///
216/// // Insert a new line after the directive
217/// let fix = directive.insert_after("add_header X-Frame-Options DENY;");
218/// assert!(fix.is_range_based());
219///
220/// // Insert before the directive
221/// let fix = directive.insert_before("# Security headers");
222/// assert!(fix.is_range_based());
223/// ```
224#[derive(Debug, Clone, Serialize, Deserialize)]
225pub struct Fix {
226    /// Line number where the fix should be applied (1-indexed)
227    pub line: usize,
228    /// The original text to replace (if None and new_text is empty, delete the line)
229    #[serde(default, skip_serializing_if = "Option::is_none")]
230    pub old_text: Option<String>,
231    /// The new text to insert (empty string with old_text=None means delete)
232    pub new_text: String,
233    /// Whether to delete the entire line
234    #[serde(default)]
235    pub delete_line: bool,
236    /// Whether to insert new_text as a new line after the specified line
237    #[serde(default)]
238    pub insert_after: bool,
239    /// Start byte offset for range-based fix (0-indexed, inclusive)
240    #[serde(default, skip_serializing_if = "Option::is_none")]
241    pub start_offset: Option<usize>,
242    /// End byte offset for range-based fix (0-indexed, exclusive)
243    #[serde(default, skip_serializing_if = "Option::is_none")]
244    pub end_offset: Option<usize>,
245}
246
247impl Fix {
248    /// Create a fix that deletes an entire line
249    pub fn delete(line: usize) -> Self {
250        Self {
251            line,
252            old_text: None,
253            new_text: String::new(),
254            delete_line: true,
255            insert_after: false,
256            start_offset: None,
257            end_offset: None,
258        }
259    }
260
261    /// Create a fix that inserts a new line after the specified line
262    pub fn insert_after(line: usize, new_text: &str) -> Self {
263        Self {
264            line,
265            old_text: None,
266            new_text: new_text.to_string(),
267            delete_line: false,
268            insert_after: true,
269            start_offset: None,
270            end_offset: None,
271        }
272    }
273
274    /// Create a range-based fix that replaces bytes from start to end offset
275    ///
276    /// This allows multiple fixes on the same line as long as their ranges don't overlap.
277    pub fn replace_range(start_offset: usize, end_offset: usize, new_text: &str) -> Self {
278        Self {
279            line: 0, // Not used for range-based fixes
280            old_text: None,
281            new_text: new_text.to_string(),
282            delete_line: false,
283            insert_after: false,
284            start_offset: Some(start_offset),
285            end_offset: Some(end_offset),
286        }
287    }
288
289    /// Check if this is a range-based fix
290    pub fn is_range_based(&self) -> bool {
291        self.start_offset.is_some() && self.end_offset.is_some()
292    }
293}
294
295/// A lint error reported by a plugin.
296///
297/// Create errors using [`LintError::error()`] / [`LintError::warning()`] directly,
298/// or more conveniently via [`ErrorBuilder`] (obtained from [`PluginSpec::error_builder()`]):
299///
300/// ```
301/// use nginx_lint_plugin::prelude::*;
302///
303/// let spec = PluginSpec::new("my-rule", "security", "Check something");
304/// let err = spec.error_builder();
305///
306/// // Warning at a specific line/column
307/// let warning = err.warning("message", 10, 5);
308/// assert_eq!(warning.line, Some(10));
309///
310/// // Warning at a directive's location (most common pattern)
311/// let config = nginx_lint_plugin::parse_string("autoindex on;").unwrap();
312/// let directive = config.all_directives().next().unwrap();
313/// let error = err.warning_at("use 'off'", directive)
314///     .with_fix(directive.replace_with("autoindex off;"));
315/// assert_eq!(error.fixes.len(), 1);
316/// ```
317#[derive(Debug, Clone, Serialize, Deserialize)]
318pub struct LintError {
319    pub rule: String,
320    pub category: String,
321    pub message: String,
322    pub severity: Severity,
323    #[serde(default, skip_serializing_if = "Option::is_none")]
324    pub line: Option<usize>,
325    #[serde(default, skip_serializing_if = "Option::is_none")]
326    pub column: Option<usize>,
327    #[serde(default, skip_serializing_if = "Vec::is_empty")]
328    pub fixes: Vec<Fix>,
329}
330
331impl LintError {
332    /// Create a new error with Error severity
333    pub fn error(rule: &str, category: &str, message: &str, line: usize, column: usize) -> Self {
334        Self {
335            rule: rule.to_string(),
336            category: category.to_string(),
337            message: message.to_string(),
338            severity: Severity::Error,
339            line: if line > 0 { Some(line) } else { None },
340            column: if column > 0 { Some(column) } else { None },
341            fixes: Vec::new(),
342        }
343    }
344
345    /// Create a new error with Warning severity
346    pub fn warning(rule: &str, category: &str, message: &str, line: usize, column: usize) -> Self {
347        Self {
348            rule: rule.to_string(),
349            category: category.to_string(),
350            message: message.to_string(),
351            severity: Severity::Warning,
352            line: if line > 0 { Some(line) } else { None },
353            column: if column > 0 { Some(column) } else { None },
354            fixes: Vec::new(),
355        }
356    }
357
358    /// Attach a fix to this error
359    pub fn with_fix(mut self, fix: Fix) -> Self {
360        self.fixes.push(fix);
361        self
362    }
363
364    /// Attach multiple fixes to this error
365    pub fn with_fixes(mut self, fixes: Vec<Fix>) -> Self {
366        self.fixes.extend(fixes);
367        self
368    }
369}
370
371/// Trait that all plugins must implement.
372///
373/// A plugin consists of two parts:
374/// - **Metadata** ([`spec()`](Plugin::spec)) describing the rule name, category, severity, and documentation
375/// - **Logic** ([`check()`](Plugin::check)) that inspects the parsed nginx config and reports errors
376///
377/// Plugins must also derive [`Default`], which is used by [`export_plugin!`](crate::export_plugin)
378/// to instantiate the plugin.
379///
380/// # Example
381///
382/// ```
383/// use nginx_lint_plugin::prelude::*;
384///
385/// #[derive(Default)]
386/// pub struct MyPlugin;
387///
388/// impl Plugin for MyPlugin {
389///     fn spec(&self) -> PluginSpec {
390///         PluginSpec::new("my-rule", "security", "Check for something")
391///             .with_severity("warning")
392///     }
393///
394///     fn check(&self, config: &Config, _path: &str) -> Vec<LintError> {
395///         let mut errors = Vec::new();
396///         let err = self.spec().error_builder();
397///
398///         for ctx in config.all_directives_with_context() {
399///             if ctx.is_inside("http") && ctx.directive.is("bad_directive") {
400///                 errors.push(err.warning_at("Avoid bad_directive", ctx.directive));
401///             }
402///         }
403///         errors
404///     }
405/// }
406///
407/// // export_plugin!(MyPlugin);  // Required for WASM build
408///
409/// // Verify it works
410/// let plugin = MyPlugin;
411/// let config = nginx_lint_plugin::parse_string("http { bad_directive on; }").unwrap();
412/// let errors = plugin.check(&config, "test.conf");
413/// assert_eq!(errors.len(), 1);
414/// ```
415pub trait Plugin: Default {
416    /// Return plugin metadata.
417    ///
418    /// This is called once at plugin load time. Use [`PluginSpec::new()`] to create
419    /// the spec, then chain builder methods like [`with_severity()`](PluginSpec::with_severity),
420    /// [`with_why()`](PluginSpec::with_why), [`with_bad_example()`](PluginSpec::with_bad_example), etc.
421    fn spec(&self) -> PluginSpec;
422
423    /// Check the configuration and return any lint errors.
424    ///
425    /// Called once per file being linted. The `config` parameter contains the parsed
426    /// AST of the nginx configuration file. The `path` parameter is the file path
427    /// being checked (useful for error messages).
428    ///
429    /// Use [`config.all_directives()`](ConfigExt::all_directives) for simple iteration
430    /// or [`config.all_directives_with_context()`](ConfigExt::all_directives_with_context)
431    /// when you need to know the parent block context.
432    fn check(&self, config: &Config, path: &str) -> Vec<LintError>;
433}
434
435// Re-export AST types from nginx-lint-common
436pub use nginx_lint_common::parser::ast::{
437    Argument, ArgumentValue, Block, Comment, Config, ConfigItem, Directive, Position, Span,
438};
439
440/// Extension trait for [`Config`] providing iteration and include-context helpers.
441///
442/// This trait is automatically available when using `use nginx_lint_plugin::prelude::*`.
443///
444/// # Traversal
445///
446/// Two traversal methods are provided:
447///
448/// - [`all_directives()`](ConfigExt::all_directives) - Simple recursive iteration over all directives
449/// - [`all_directives_with_context()`](ConfigExt::all_directives_with_context) - Iteration with
450///   parent block context (e.g., know if a directive is inside `http`, `server`, `location`)
451///
452/// # Include Context
453///
454/// When nginx-lint processes `include` directives, the included file's [`Config`] receives
455/// an `include_context` field recording the parent block names. For example, a file included
456/// from `http { server { include conf.d/*.conf; } }` would have
457/// `include_context = ["http", "server"]`.
458///
459/// The `is_included_from_*` methods check this context:
460///
461/// ```
462/// use nginx_lint_plugin::prelude::*;
463///
464/// let mut config = nginx_lint_plugin::parse_string("server { listen 80; }").unwrap();
465/// assert!(!config.is_included_from_http());
466///
467/// // Simulate being included from http context
468/// config.include_context = vec!["http".to_string()];
469/// assert!(config.is_included_from_http());
470/// ```
471pub trait ConfigExt {
472    /// Iterate over all directives recursively.
473    ///
474    /// Traverses the entire config tree depth-first, yielding each [`Directive`].
475    fn all_directives(&self) -> AllDirectivesIter<'_>;
476
477    /// Iterate over all directives with parent context information.
478    ///
479    /// Each item is a [`DirectiveWithContext`] that includes the parent block stack.
480    /// This is the recommended traversal method for most plugins, as it allows
481    /// checking whether a directive is inside a specific block (e.g., `http`, `server`).
482    fn all_directives_with_context(&self) -> AllDirectivesWithContextIter<'_>;
483
484    /// Check if this config is included from within a specific context.
485    fn is_included_from(&self, context: &str) -> bool;
486
487    /// Check if this config is included from within `http` context.
488    fn is_included_from_http(&self) -> bool;
489
490    /// Check if this config is included from within `http > server` context.
491    fn is_included_from_http_server(&self) -> bool;
492
493    /// Check if this config is included from within `http > ... > location` context.
494    fn is_included_from_http_location(&self) -> bool;
495
496    /// Check if this config is included from within `stream` context.
497    fn is_included_from_stream(&self) -> bool;
498
499    /// Get the immediate parent context (last element in include_context).
500    fn immediate_parent_context(&self) -> Option<&str>;
501}
502
503impl ConfigExt for Config {
504    fn all_directives(&self) -> AllDirectivesIter<'_> {
505        AllDirectivesIter {
506            stack: vec![self.items.iter()],
507        }
508    }
509
510    fn all_directives_with_context(&self) -> AllDirectivesWithContextIter<'_> {
511        let initial_context: Vec<String> = self.include_context.clone();
512        AllDirectivesWithContextIter::new(&self.items, initial_context)
513    }
514
515    fn is_included_from(&self, context: &str) -> bool {
516        self.include_context.iter().any(|c| c == context)
517    }
518
519    fn is_included_from_http(&self) -> bool {
520        self.is_included_from("http")
521    }
522
523    fn is_included_from_http_server(&self) -> bool {
524        let ctx = &self.include_context;
525        ctx.iter().any(|c| c == "http")
526            && ctx.iter().any(|c| c == "server")
527            && ctx.iter().position(|c| c == "http") < ctx.iter().position(|c| c == "server")
528    }
529
530    fn is_included_from_http_location(&self) -> bool {
531        let ctx = &self.include_context;
532        ctx.iter().any(|c| c == "http")
533            && ctx.iter().any(|c| c == "location")
534            && ctx.iter().position(|c| c == "http") < ctx.iter().position(|c| c == "location")
535    }
536
537    fn is_included_from_stream(&self) -> bool {
538        self.is_included_from("stream")
539    }
540
541    fn immediate_parent_context(&self) -> Option<&str> {
542        self.include_context.last().map(|s| s.as_str())
543    }
544}
545
546/// Iterator over all directives in a config (recursively)
547pub struct AllDirectivesIter<'a> {
548    stack: Vec<std::slice::Iter<'a, ConfigItem>>,
549}
550
551impl<'a> Iterator for AllDirectivesIter<'a> {
552    type Item = &'a Directive;
553
554    fn next(&mut self) -> Option<Self::Item> {
555        while let Some(iter) = self.stack.last_mut() {
556            if let Some(item) = iter.next() {
557                if let ConfigItem::Directive(directive) = item {
558                    if let Some(block) = &directive.block {
559                        self.stack.push(block.items.iter());
560                    }
561                    return Some(directive.as_ref());
562                }
563            } else {
564                self.stack.pop();
565            }
566        }
567        None
568    }
569}
570
571/// A directive paired with its parent block context.
572///
573/// Yielded by [`ConfigExt::all_directives_with_context()`]. Provides methods to
574/// query the parent block hierarchy without manually tracking nesting.
575///
576/// # Example
577///
578/// ```
579/// use nginx_lint_plugin::prelude::*;
580///
581/// let config = nginx_lint_plugin::parse_string(
582///     "http {\n    server {\n        listen 80;\n    }\n}"
583/// ).unwrap();
584///
585/// for ctx in config.all_directives_with_context() {
586///     if ctx.is_inside("http") && ctx.directive.is("listen") {
587///         assert!(ctx.parent_is("server"));
588///         assert_eq!(ctx.depth, 2);
589///     }
590/// }
591/// ```
592#[derive(Debug, Clone)]
593pub struct DirectiveWithContext<'a> {
594    /// The directive itself.
595    pub directive: &'a Directive,
596    /// Stack of parent directive names (e.g., `["http", "server"]`).
597    pub parent_stack: Vec<String>,
598    /// Nesting depth (0 = root level).
599    pub depth: usize,
600}
601
602impl<'a> DirectiveWithContext<'a> {
603    /// Get the immediate parent directive name, if any
604    pub fn parent(&self) -> Option<&str> {
605        self.parent_stack.last().map(|s| s.as_str())
606    }
607
608    /// Check if this directive is inside a specific parent context
609    pub fn is_inside(&self, parent_name: &str) -> bool {
610        self.parent_stack.iter().any(|p| p == parent_name)
611    }
612
613    /// Check if the immediate parent is a specific directive
614    pub fn parent_is(&self, parent_name: &str) -> bool {
615        self.parent() == Some(parent_name)
616    }
617
618    /// Check if this directive is at root level
619    pub fn is_at_root(&self) -> bool {
620        self.parent_stack.is_empty()
621    }
622}
623
624/// Iterator over all directives with their parent context
625pub struct AllDirectivesWithContextIter<'a> {
626    stack: Vec<(std::slice::Iter<'a, ConfigItem>, Option<String>)>,
627    current_parents: Vec<String>,
628}
629
630impl<'a> AllDirectivesWithContextIter<'a> {
631    fn new(items: &'a [ConfigItem], initial_context: Vec<String>) -> Self {
632        Self {
633            stack: vec![(items.iter(), None)],
634            current_parents: initial_context,
635        }
636    }
637}
638
639impl<'a> Iterator for AllDirectivesWithContextIter<'a> {
640    type Item = DirectiveWithContext<'a>;
641
642    fn next(&mut self) -> Option<Self::Item> {
643        while let Some((iter, _)) = self.stack.last_mut() {
644            if let Some(item) = iter.next() {
645                if let ConfigItem::Directive(directive) = item {
646                    let context = DirectiveWithContext {
647                        directive: directive.as_ref(),
648                        parent_stack: self.current_parents.clone(),
649                        depth: self.current_parents.len(),
650                    };
651
652                    if let Some(block) = &directive.block {
653                        self.current_parents.push(directive.name.clone());
654                        self.stack
655                            .push((block.items.iter(), Some(directive.name.clone())));
656                    }
657
658                    return Some(context);
659                }
660            } else {
661                let (_, parent_name) = self.stack.pop().unwrap();
662                if parent_name.is_some() {
663                    self.current_parents.pop();
664                }
665            }
666        }
667        None
668    }
669}
670
671/// Extension trait for [`Directive`] providing inspection and fix-generation helpers.
672///
673/// This trait adds convenience methods to [`Directive`] for:
674/// - **Inspection**: [`is()`](DirectiveExt::is), [`first_arg()`](DirectiveExt::first_arg),
675///   [`has_arg()`](DirectiveExt::has_arg), etc.
676/// - **Fix generation**: [`replace_with()`](DirectiveExt::replace_with),
677///   [`delete_line()`](DirectiveExt::delete_line), [`insert_after()`](DirectiveExt::insert_after), etc.
678///
679/// # Example
680///
681/// ```
682/// use nginx_lint_plugin::prelude::*;
683///
684/// let config = nginx_lint_plugin::parse_string(
685///     "proxy_pass http://backend;"
686/// ).unwrap();
687/// let directive = config.all_directives().next().unwrap();
688///
689/// assert!(directive.is("proxy_pass"));
690/// assert_eq!(directive.first_arg(), Some("http://backend"));
691/// assert_eq!(directive.arg_count(), 1);
692///
693/// // Generate a fix to replace the directive
694/// let fix = directive.replace_with("proxy_pass http://new-backend;");
695/// assert!(fix.is_range_based());
696/// ```
697pub trait DirectiveExt {
698    /// Check if the directive has the given name.
699    fn is(&self, name: &str) -> bool;
700    /// Get the first argument's string value, if any.
701    fn first_arg(&self) -> Option<&str>;
702    /// Check if the first argument equals the given value.
703    fn first_arg_is(&self, value: &str) -> bool;
704    /// Get the argument at the given index.
705    fn arg_at(&self, index: usize) -> Option<&str>;
706    /// Get the last argument's string value, if any.
707    fn last_arg(&self) -> Option<&str>;
708    /// Check if any argument equals the given value.
709    fn has_arg(&self, value: &str) -> bool;
710    /// Return the number of arguments.
711    fn arg_count(&self) -> usize;
712    /// Get the byte offset including leading whitespace.
713    fn full_start_offset(&self) -> usize;
714    /// Create a [`Fix`] that replaces this directive with new text, preserving indentation.
715    fn replace_with(&self, new_text: &str) -> Fix;
716    /// Create a [`Fix`] that deletes this directive's line.
717    fn delete_line(&self) -> Fix;
718    /// Create a [`Fix`] that inserts a new line after this directive, matching indentation.
719    fn insert_after(&self, new_text: &str) -> Fix;
720    /// Create a [`Fix`] that inserts multiple new lines after this directive.
721    fn insert_after_many(&self, lines: &[&str]) -> Fix;
722    /// Create a [`Fix`] that inserts a new line before this directive, matching indentation.
723    fn insert_before(&self, new_text: &str) -> Fix;
724    /// Create a [`Fix`] that inserts multiple new lines before this directive.
725    fn insert_before_many(&self, lines: &[&str]) -> Fix;
726}
727
728impl DirectiveExt for Directive {
729    fn is(&self, name: &str) -> bool {
730        self.name == name
731    }
732
733    fn first_arg(&self) -> Option<&str> {
734        self.args.first().map(|a| a.as_str())
735    }
736
737    fn first_arg_is(&self, value: &str) -> bool {
738        self.first_arg() == Some(value)
739    }
740
741    fn arg_at(&self, index: usize) -> Option<&str> {
742        self.args.get(index).map(|a| a.as_str())
743    }
744
745    fn last_arg(&self) -> Option<&str> {
746        self.args.last().map(|a| a.as_str())
747    }
748
749    fn has_arg(&self, value: &str) -> bool {
750        self.args.iter().any(|a| a.as_str() == value)
751    }
752
753    fn arg_count(&self) -> usize {
754        self.args.len()
755    }
756
757    fn full_start_offset(&self) -> usize {
758        self.span.start.offset - self.leading_whitespace.len()
759    }
760
761    fn replace_with(&self, new_text: &str) -> Fix {
762        let start = self.full_start_offset();
763        let end = self.span.end.offset;
764        let fixed = format!("{}{}", self.leading_whitespace, new_text);
765        Fix::replace_range(start, end, &fixed)
766    }
767
768    fn delete_line(&self) -> Fix {
769        Fix::delete(self.span.start.line)
770    }
771
772    fn insert_after(&self, new_text: &str) -> Fix {
773        self.insert_after_many(&[new_text])
774    }
775
776    fn insert_after_many(&self, lines: &[&str]) -> Fix {
777        let indent = " ".repeat(self.span.start.column.saturating_sub(1));
778        let fix_text: String = lines
779            .iter()
780            .map(|line| format!("\n{}{}", indent, line))
781            .collect();
782        let insert_offset = self.span.end.offset;
783        Fix::replace_range(insert_offset, insert_offset, &fix_text)
784    }
785
786    fn insert_before(&self, new_text: &str) -> Fix {
787        self.insert_before_many(&[new_text])
788    }
789
790    fn insert_before_many(&self, lines: &[&str]) -> Fix {
791        let indent = " ".repeat(self.span.start.column.saturating_sub(1));
792        let fix_text: String = lines
793            .iter()
794            .map(|line| format!("{}{}\n", indent, line))
795            .collect();
796        let line_start_offset = self.span.start.offset - (self.span.start.column - 1);
797        Fix::replace_range(line_start_offset, line_start_offset, &fix_text)
798    }
799}
800
801/// Extension trait for Argument to add source reconstruction
802pub trait ArgumentExt {
803    /// Reconstruct the source text for this argument
804    fn to_source(&self) -> String;
805}
806
807impl ArgumentExt for Argument {
808    fn to_source(&self) -> String {
809        match &self.value {
810            ArgumentValue::Literal(s) => s.clone(),
811            ArgumentValue::QuotedString(s) => format!("\"{}\"", s),
812            ArgumentValue::SingleQuotedString(s) => format!("'{}'", s),
813            ArgumentValue::Variable(s) => format!("${}", s),
814        }
815    }
816}