alef_e2e/
format.rs

1//! Post-generation formatter support for e2e test projects.
2//!
3//! Reads formatter commands from `E2eConfig.format` and runs them for each
4//! language that had files generated. The `{dir}` placeholder in the command
5//! is replaced with the actual output directory.
6
7use crate::config::E2eConfig;
8use alef_core::backend::GeneratedFile;
9use std::collections::HashSet;
10use std::path::Path;
11use tracing::warn;
12
13/// Default per-language formatter commands for e2e directories.
14///
15/// These are run automatically when the language's directory was generated and
16/// no custom override is present in `e2e_config.format`. The `{dir}` placeholder
17/// is replaced with the actual output directory path before execution.
18///
19/// * `rust` — `(cd {dir} && cargo fmt --all)` formats the standalone e2e crate
20///   from inside its own directory. `cargo fmt --manifest-path` is *not* a
21///   global cargo flag (it's an unstable cargo-fmt-only flag in nightly), so
22///   running cargo fmt from the e2e crate's own directory is the portable way
23///   to format a non-workspace-member crate.
24/// * `python` — `ruff format {dir}` normalises whitespace/newlines in the
25///   generated test files so prek's ruff hook is a no-op.
26fn default_formatter(lang: &str) -> Option<&'static str> {
27    match lang {
28        "rust" => Some("(cd {dir} && cargo fmt --all)"),
29        "python" => Some("ruff format {dir}"),
30        _ => None,
31    }
32}
33
34/// Run per-language formatters for all languages that had files generated.
35///
36/// For each language present in `files`, picks the command from
37/// `e2e_config.format[lang]` when available, then falls back to
38/// [`default_formatter`] for languages that have a built-in default (rust,
39/// python). The `{dir}` placeholder is replaced with `{output}/{lang}`.
40/// Failures are logged as warnings and do not abort the process.
41pub fn run_formatters(files: &[GeneratedFile], e2e_config: &E2eConfig) {
42    // Collect the set of languages that had files generated by inspecting
43    // file paths. E2e files are written to `{output}/{lang}/...`, so the
44    // first path component after the output prefix is the language name.
45    let output_prefix = Path::new(e2e_config.effective_output());
46    let languages: HashSet<String> = files
47        .iter()
48        .filter_map(|f| {
49            let remainder = f.path.strip_prefix(output_prefix).ok()?;
50            let first = remainder.components().next()?;
51            Some(first.as_os_str().to_string_lossy().into_owned())
52        })
53        .collect();
54
55    for lang in &languages {
56        // User override takes precedence; then built-in default.
57        let cmd_template: &str = if let Some(custom) = e2e_config.format.get(lang.as_str()) {
58            custom.as_str()
59        } else if let Some(builtin) = default_formatter(lang.as_str()) {
60            builtin
61        } else {
62            continue;
63        };
64
65        let dir = format!("{}/{}", e2e_config.effective_output(), lang);
66        let cmd = cmd_template.replace("{dir}", &dir);
67
68        eprintln!("  Formatting {lang}: {cmd}");
69        let status = std::process::Command::new("sh").args(["-c", &cmd]).status();
70
71        match status {
72            Ok(s) if s.success() => {}
73            Ok(s) => {
74                warn!("Formatter for {lang} exited with {s}: {cmd}");
75            }
76            Err(e) => {
77                warn!("Failed to run formatter for {lang}: {e}");
78            }
79        }
80    }
81}
82
83#[cfg(test)]
84mod tests {
85    use super::*;
86
87    #[test]
88    fn test_default_formatter_rust_uses_cd_into_dir() {
89        let cmd = default_formatter("rust").expect("rust must have a default formatter");
90        assert!(
91            cmd.contains("cd {dir}") && cmd.contains("cargo fmt"),
92            "rust formatter must cd into {{dir}} before invoking cargo fmt so it works on \
93             standalone (non-workspace-member) e2e crates: {cmd}"
94        );
95        assert!(
96            !cmd.contains("--manifest-path"),
97            "rust formatter must not use --manifest-path; cargo-fmt does not accept it as a \
98             global flag: {cmd}"
99        );
100        assert!(
101            cmd.contains("{dir}"),
102            "rust formatter must include {{dir}} placeholder: {cmd}"
103        );
104    }
105
106    #[test]
107    fn test_default_formatter_python_uses_ruff_format() {
108        let cmd = default_formatter("python").expect("python must have a default formatter");
109        assert!(cmd.contains("ruff"), "python formatter must use ruff: {cmd}");
110        assert!(cmd.contains("format"), "python formatter must run ruff format: {cmd}");
111        assert!(
112            cmd.contains("{dir}"),
113            "python formatter must include {{dir}} placeholder: {cmd}"
114        );
115    }
116
117    #[test]
118    fn test_default_formatter_unknown_lang_returns_none() {
119        assert!(default_formatter("gleam").is_none());
120        assert!(default_formatter("zig").is_none());
121        assert!(default_formatter("java").is_none());
122    }
123}
alef_e2e/format.rs

alef_e2e/
format.rs
