code_moniker_cli/
lang.rs

1use std::path::Path;
2
3use thiserror::Error;
4
5use code_moniker_core::lang::Lang;
6
7#[derive(Debug, Error)]
8pub enum LangError {
9	#[error(
10		"unsupported file extension `.{0}` (known: ts/tsx/js/jsx/mjs/cjs, rs, java, py/pyi, go, cs, sql/plpgsql)"
11	)]
12	UnknownExtension(String),
13	#[error("file has no extension; cannot infer language")]
14	NoExtension,
15}
16
17pub fn path_to_lang(path: &Path) -> Result<Lang, LangError> {
18	let ext = path
19		.extension()
20		.and_then(|s| s.to_str())
21		.map(|s| s.to_ascii_lowercase());
22	let ext = match ext.as_deref() {
23		Some("") | None => return Err(LangError::NoExtension),
24		Some(e) => e,
25	};
26	match ext {
27		"ts" | "tsx" | "js" | "jsx" | "mjs" | "cjs" => Ok(Lang::Ts),
28		"rs" => Ok(Lang::Rs),
29		"java" => Ok(Lang::Java),
30		"py" | "pyi" => Ok(Lang::Python),
31		"go" => Ok(Lang::Go),
32		"cs" => Ok(Lang::Cs),
33		"sql" | "plpgsql" => Ok(Lang::Sql),
34		other => Err(LangError::UnknownExtension(other.to_string())),
35	}
36}
37
38#[cfg(test)]
39mod tests {
40	use super::*;
41	use std::path::PathBuf;
42
43	fn dispatch(s: &str) -> Result<Lang, LangError> {
44		path_to_lang(&PathBuf::from(s))
45	}
46
47	#[test]
48	fn ts_family_resolves_to_ts() {
49		for p in &[
50			"x.ts",
51			"x.tsx",
52			"x.js",
53			"x.jsx",
54			"x.mjs",
55			"x.cjs",
56			"a/b/c/x.TS",
57		] {
58			assert_eq!(dispatch(p).unwrap(), Lang::Ts, "{p}");
59		}
60	}
61
62	#[test]
63	fn each_supported_extension_resolves() {
64		assert_eq!(dispatch("a.rs").unwrap(), Lang::Rs);
65		assert_eq!(dispatch("a.java").unwrap(), Lang::Java);
66		assert_eq!(dispatch("a.py").unwrap(), Lang::Python);
67		assert_eq!(dispatch("a.pyi").unwrap(), Lang::Python);
68		assert_eq!(dispatch("a.go").unwrap(), Lang::Go);
69		assert_eq!(dispatch("a.cs").unwrap(), Lang::Cs);
70	}
71
72	#[test]
73	fn unknown_extension_errors() {
74		match dispatch("a.txt") {
75			Err(LangError::UnknownExtension(s)) => assert_eq!(s, "txt"),
76			other => panic!("unexpected: {other:?}"),
77		}
78	}
79
80	#[test]
81	fn missing_extension_errors() {
82		match dispatch("Makefile") {
83			Err(LangError::NoExtension) => {}
84			other => panic!("unexpected: {other:?}"),
85		}
86	}
87
88	#[test]
89	fn case_is_insensitive() {
90		assert_eq!(dispatch("X.JAVA").unwrap(), Lang::Java);
91		assert_eq!(dispatch("X.RS").unwrap(), Lang::Rs);
92	}
93
94	#[test]
95	fn sql_extension_resolves() {
96		assert_eq!(dispatch("a.sql").unwrap(), Lang::Sql);
97		assert_eq!(dispatch("a.plpgsql").unwrap(), Lang::Sql);
98	}
99}
code_moniker_cli/lang.rs

code_moniker_cli/
lang.rs
