alef_e2e/codegen/
mod.rs

1//! E2e test code generation trait and language dispatch.
2//!
3//! ## DRY layer ([`client`])
4//!
5//! Per-language e2e codegen historically duplicated the structural shape of every
6//! test (function header, request build, response assert) and only differed in
7//! syntax. The [`client`] submodule pulls that shape into trait + driver pairs
8//! ([`client::TestClientRenderer`] + [`client::http_call::render_http_test`])
9//! so each language can be migrated to TestClient-driven tests by:
10//!
11//! 1. Implementing `TestClientRenderer` once per language (small, mechanical).
12//! 2. Replacing the language's monolithic `render_http_test_function` with a
13//!    call to `client::http_call::render_http_test(out, &MyRenderer, fixture)`.
14//! 3. Optionally splitting the per-language file into a directory
15//!    `<lang>/{mod.rs,client.rs,ws.rs,helpers.rs}` when the file gets unwieldy.
16//!
17//! Until a language migrates, it continues using the legacy monolithic renderer —
18//! both can coexist behind the per-language [`E2eCodegen::generate`] entry.
19
20pub mod brew;
21pub mod c;
22pub mod client;
23pub mod csharp;
24pub mod dart;
25mod dart_visitors;
26pub mod elixir;
27pub mod gleam;
28pub mod go;
29pub mod java;
30pub mod kotlin;
31pub mod kotlin_android;
32pub mod php;
33pub mod python;
34pub mod r;
35pub mod ruby;
36pub mod rust;
37pub mod streaming_assertions;
38pub mod swift;
39pub mod typescript;
40pub mod wasm;
41pub mod zig;
42mod zig_visitors;
43
44use crate::config::E2eConfig;
45use crate::fixture::{Fixture, FixtureGroup};
46use alef_core::backend::GeneratedFile;
47use alef_core::config::ResolvedCrateConfig;
48use alef_core::ir::TypeDef;
49use anyhow::Result;
50
51/// Check if a fixture should be included for the given language.
52///
53/// Returns false if:
54/// - The fixture's resolved category is in `e2e_config.exclude_categories`
55///   (fixture is excluded from every language's cross-language e2e codegen)
56/// - The fixture has a skip condition that applies to this language
57/// - The fixture's call has no resolvable function for this language (no base
58///   `function` set and no override for the language). Calls that share a base
59///   function but only carry per-language type/arg overrides are still emitted
60///   for languages without an explicit override.
61pub(crate) fn should_include_fixture(fixture: &Fixture, language: &str, e2e_config: &E2eConfig) -> bool {
62    if !e2e_config.exclude_categories.is_empty() && e2e_config.exclude_categories.contains(&fixture.resolved_category())
63    {
64        return false;
65    }
66    if let Some(skip) = &fixture.skip {
67        if skip.should_skip(language) {
68            return false;
69        }
70    }
71    let call_config = e2e_config.resolve_call_for_fixture(fixture.call.as_deref(), &fixture.input);
72    // Also respect skip_languages on the resolved call (e.g. batch_scrape skips elixir).
73    if call_config.skip_languages.iter().any(|l| l == language) {
74        return false;
75    }
76    if call_config.function.is_empty() && !call_config.overrides.contains_key(language) {
77        return false;
78    }
79    true
80}
81
82/// Recursively rewrite a JSON value's object keys to the target wire case.
83///
84/// `wire_case` accepts the same vocabulary as serde's `rename_all` attribute:
85/// `"snake_case"` (default), `"camelCase"`, `"PascalCase"`, `"SCREAMING_SNAKE_CASE"`,
86/// `"kebab-case"`, `"SCREAMING-KEBAB-CASE"`. Unknown values fall back to `snake_case`.
87///
88/// Used by per-language e2e codegen to translate canonical (snake_case) fixture keys
89/// to the wire case that each binding's `from_json` / typed deserializer expects, as
90/// driven by `ResolvedCrateConfig::serde_rename_all_for_language`.
91pub(crate) fn transform_json_keys_for_language(value: &serde_json::Value, wire_case: &str) -> serde_json::Value {
92    use heck::{ToKebabCase, ToLowerCamelCase, ToPascalCase, ToShoutyKebabCase, ToShoutySnakeCase, ToSnakeCase};
93    let rewrite_key: fn(&str) -> String = match wire_case {
94        "camelCase" => |k| k.to_lower_camel_case(),
95        "PascalCase" => |k| k.to_pascal_case(),
96        "SCREAMING_SNAKE_CASE" => |k| k.to_shouty_snake_case(),
97        "kebab-case" => |k| k.to_kebab_case(),
98        "SCREAMING-KEBAB-CASE" => |k| k.to_shouty_kebab_case(),
99        _ => |k| k.to_snake_case(),
100    };
101    fn walk(value: &serde_json::Value, rewrite_key: fn(&str) -> String) -> serde_json::Value {
102        match value {
103            serde_json::Value::Object(obj) => {
104                let new_obj: serde_json::Map<String, serde_json::Value> = obj
105                    .iter()
106                    .map(|(k, v)| (rewrite_key(k), walk(v, rewrite_key)))
107                    .collect();
108                serde_json::Value::Object(new_obj)
109            }
110            serde_json::Value::Array(arr) => {
111                serde_json::Value::Array(arr.iter().map(|v| walk(v, rewrite_key)).collect())
112            }
113            other => other.clone(),
114        }
115    }
116    walk(value, rewrite_key)
117}
118
119/// Trait for per-language e2e test code generation.
120pub trait E2eCodegen: Send + Sync {
121    /// Generate all e2e test project files for this language.
122    ///
123    /// `type_defs` is the IR type registry extracted from the source crate.
124    /// It is used by backends that need to introspect struct field types at
125    /// codegen time (e.g. the TypeScript/WASM generator uses it to
126    /// auto-derive `nested_types` mappings for wasm-bindgen class wrapping).
127    fn generate(
128        &self,
129        groups: &[FixtureGroup],
130        e2e_config: &E2eConfig,
131        config: &ResolvedCrateConfig,
132        type_defs: &[TypeDef],
133    ) -> Result<Vec<GeneratedFile>>;
134
135    /// Language name for display and directory naming.
136    fn language_name(&self) -> &'static str;
137}
138
139/// Get all available e2e code generators.
140pub fn all_generators() -> Vec<Box<dyn E2eCodegen>> {
141    vec![
142        Box::new(rust::RustE2eCodegen),
143        Box::new(python::PythonE2eCodegen),
144        Box::new(typescript::TypeScriptCodegen),
145        Box::new(go::GoCodegen),
146        Box::new(java::JavaCodegen),
147        Box::new(kotlin::KotlinE2eCodegen),
148        Box::new(kotlin_android::KotlinAndroidE2eCodegen),
149        Box::new(csharp::CSharpCodegen),
150        Box::new(php::PhpCodegen),
151        Box::new(ruby::RubyCodegen),
152        Box::new(elixir::ElixirCodegen),
153        Box::new(gleam::GleamE2eCodegen),
154        Box::new(r::RCodegen),
155        Box::new(wasm::WasmCodegen),
156        Box::new(c::CCodegen),
157        Box::new(zig::ZigE2eCodegen),
158        Box::new(dart::DartE2eCodegen),
159        Box::new(swift::SwiftE2eCodegen),
160        Box::new(brew::BrewCodegen),
161    ]
162}
163
164/// Get e2e code generators for specific language names.
165pub fn generators_for(languages: &[String]) -> Vec<Box<dyn E2eCodegen>> {
166    all_generators()
167        .into_iter()
168        .filter(|g| languages.iter().any(|l| l == g.language_name()))
169        .collect()
170}
171
172/// Resolve a JSON field from a fixture input by path.
173///
174/// Field paths in call config are "input.path", "input.config", etc.
175/// Since we already receive `fixture.input`, strip the leading "input." prefix.
176/// When `field_path` is exactly `"input"`, the whole input object is returned.
177pub(crate) fn resolve_field<'a>(input: &'a serde_json::Value, field_path: &str) -> &'a serde_json::Value {
178    // "input" with no subpath means "the entire input object".
179    if field_path == "input" {
180        return input;
181    }
182    let path = field_path.strip_prefix("input.").unwrap_or(field_path);
183    let mut current = input;
184    for part in path.split('.') {
185        current = current.get(part).unwrap_or(&serde_json::Value::Null);
186    }
187    current
188}
alef_e2e/codegen/mod.rs

alef_e2e/codegen/
mod.rs
