feat(cargo-heather): recognize .psd1 and .psm1 as PowerShell files

crates/cargo-heather/README.md

@@ -15,7 +15,9 @@
 
 ## cargo-heather
 
-A cargo sub-command to validate license headers in Rust (`.rs`) and TOML (`.toml`) source files.
+A cargo sub-command to validate license headers in Rust (`.rs`), TOML (`.toml`),
+PowerShell (`.ps1`, `.psd1`, `.psm1`), Just (`justfile`, `*.just`), and env
+(`constants.env`) source files.
 
 ### Setup
 
@@ -57,7 +59,7 @@ exist on disk produce a warning and are ignored.
 ### Usage
 
 ```bash
-# Check all .rs and .toml files for correct license headers
+# Check all supported source files for correct license headers
 cargo heather
 
 # Automatically fix files by adding/replacing headers
@@ -116,10 +118,22 @@ Fixed 2 file(s).
 ### How it works
 
 1. **Config loading** — Reads `.cargo-heather.toml` from the project root and resolves the expected header text (from SPDX identifier or custom text).
-1. **File scanning** — Walks the project directory to find all `.rs` and `.toml` files, skipping `target/`, hidden directories, and the config file itself.
-1. **Header validation** — Extracts the first comment block from each file (`//` for Rust, `#` for TOML) and compares it to the expected header. Reports missing or mismatched headers.
+1. **File scanning** — Walks the project directory for supported source files (see [Supported file kinds](#supported-file-kinds) below), skipping `target/`, hidden directories, and the config file itself.
+1. **Header validation** — Extracts the header comment block from each file (placement depends on the file kind) and compares it to the expected header. Reports missing or mismatched headers.
 1. **Fix mode** — When `--fix` is passed, automatically prepends the correct header to files that are missing it, or replaces incorrect headers.
 
+### Supported file kinds
+
+| File                          | Comment style | Header placement                                   |
+| ----------------------------- | ------------- | -------------------------------------------------- |
+| `.rs` (regular)               | `//`          | Top of file                                        |
+| `.rs` (cargo-script)          | `#`           | Inside the `---` frontmatter                       |
+| `.toml`                       | `#`           | Top of file                                        |
+| `.ps1`, `.psd1`, `.psm1`      | `#`           | Top of file, or after a leading `#!` shebang       |
+| `*.just`, `justfile`          | `#`           | Top of file                                        |
+| `constants.env`               | `#`           | Top of file                                        |
+
+
 
 <hr/>
 <sub>

crates/cargo-heather/src/comment.rs

@@ -15,7 +15,9 @@ pub enum FileKind {
     Rust,
     /// A TOML file (`.toml`). Header uses `#` at the top.
     Toml,
-    /// A `PowerShell` script (`.ps1`). Header uses `#` at the top.
+    /// A `PowerShell` script (`.ps1`) or data/module file (`.psd1`, `.psm1`).
+    /// Header uses `#`, placed at the top of the file or immediately after a
+    /// leading `#!` shebang line if one is present.
     PowerShell,
     /// A Just recipe file (`*.just` or `justfile`). Header uses `#` at the top.
     Just,
@@ -50,7 +52,9 @@ impl FileKind {
                 }
             }
             ext if ext.eq_ignore_ascii_case("toml") => Some(Self::Toml),
-            ext if ext.eq_ignore_ascii_case("ps1") => Some(Self::PowerShell),
+            ext if ext.eq_ignore_ascii_case("ps1") || ext.eq_ignore_ascii_case("psd1") || ext.eq_ignore_ascii_case("psm1") => {
+                Some(Self::PowerShell)
+            }
             ext if ext.eq_ignore_ascii_case("just") => Some(Self::Just),
             _ => None,
         }
@@ -209,4 +213,38 @@ mod tests {
         assert!(style.is_header_comment_line("// Copyright"));
         assert!(style.is_header_comment_line("//"));
     }
+
+    #[test]
+    fn detect_powershell_script_by_ps1_extension() {
+        assert_eq!(FileKind::detect(Path::new("build.ps1"), None), Some(FileKind::PowerShell));
+        // Case-insensitive — Windows paths often surface as `.PS1`.
+        assert_eq!(FileKind::detect(Path::new("BUILD.PS1"), None), Some(FileKind::PowerShell));
+    }
+
+    #[test]
+    fn detect_powershell_data_file_by_psd1_extension() {
+        // `.psd1` is plain PowerShell data syntax with the same `#`
+        // line-comment style as `.ps1`; should be classified as
+        // PowerShell so `cargo-heather` can validate / fix headers.
+        assert_eq!(FileKind::detect(Path::new("Module.psd1"), None), Some(FileKind::PowerShell));
+        assert_eq!(FileKind::detect(Path::new("scenario.psd1"), None), Some(FileKind::PowerShell));
+        assert_eq!(FileKind::detect(Path::new("MODULE.PSD1"), None), Some(FileKind::PowerShell));
+    }
+
+    #[test]
+    fn detect_powershell_module_by_psm1_extension() {
+        // `.psm1` is a PowerShell module file; same `#` comment style as `.ps1`.
+        assert_eq!(FileKind::detect(Path::new("Module.psm1"), None), Some(FileKind::PowerShell));
+        assert_eq!(FileKind::detect(Path::new("MODULE.PSM1"), None), Some(FileKind::PowerShell));
+    }
+
+    #[test]
+    fn detect_returns_none_for_unsupported_extensions() {
+        assert_eq!(FileKind::detect(Path::new("notes.txt"), None), None);
+        assert_eq!(FileKind::detect(Path::new("README.md"), None), None);
+        // Confirm we did not start matching on a substring (e.g. `ps`, `psd`).
+        assert_eq!(FileKind::detect(Path::new("a.ps"), None), None);
+        assert_eq!(FileKind::detect(Path::new("a.psd"), None), None);
+        assert_eq!(FileKind::detect(Path::new("a.psm"), None), None);
+    }
 }

crates/cargo-heather/src/lib.rs

@@ -42,7 +42,8 @@
 //!
 //! - [`FileKind::Rust`] — regular Rust source (`//` comments).
 //! - [`FileKind::Toml`] — TOML files (`#` comments).
-//! - [`FileKind::PowerShell`] — `PowerShell` scripts (`#` comments).
+//! - [`FileKind::PowerShell`] — `PowerShell` scripts (`.ps1`), data
+//!   files (`.psd1`), and module files (`.psm1`) (all use `#` comments).
 //! - [`FileKind::Just`] — Just recipes (`#` comments).
 //! - [`FileKind::Env`] — `constants.env` files (`#` comments).
 //! - [`FileKind::CargoScript`] — Rust script with shebang + `---`

crates/cargo-heather/tests/cli.rs

@@ -392,6 +392,12 @@ fn scanner_includes_legacy_hash_comment_file_types() {
         &p.join("build.ps1"),
         &format!("#!/usr/bin/env pwsh\n{HEADER_TEXT_HASH}\nWrite-Host 'ok'\n"),
     );
+    // `.psd1` is plain PowerShell data syntax (used for module manifests
+    // and config-style hashtables) and `.psm1` is a PowerShell module file;
+    // both use the same `#` line-comment syntax as `.ps1` and must be
+    // scanned alongside it.
+    write(&p.join("Settings.psd1"), &format!("{HEADER_TEXT_HASH}\n@{{ Name = 'Settings' }}\n"));
+    write(&p.join("Module.psm1"), &format!("{HEADER_TEXT_HASH}\nfunction Get-Foo {{ }}\n"));
     write(&p.join("recipes.just"), &format!("{HEADER_TEXT_HASH}\nbuild:\n    cargo build\n"));
     write(&p.join("justfile"), &format!("{HEADER_TEXT_HASH}\ntest:\n    cargo test\n"));
     write(&p.join("constants.env"), &format!("{HEADER_TEXT_HASH}\nRUST_LATEST=1.88.0\n"));
@@ -402,9 +408,9 @@ fn scanner_includes_legacy_hash_comment_file_types() {
         out.status.success(),
         "legacy hash-comment files should be checked and pass: {stderr}"
     );
-    assert!(stderr.contains("Checking 4 file(s)"), "{stderr}");
+    assert!(stderr.contains("Checking 6 file(s)"), "{stderr}");
     assert!(
-        stderr.contains("All 4 file(s) have correct license headers."),
+        stderr.contains("All 6 file(s) have correct license headers."),
         "summary missing for legacy hash-comment files: {stderr}"
     );
 }
@@ -422,6 +428,35 @@ fn scanner_reports_missing_header_in_legacy_hash_comment_file_type() {
     assert!(stderr.contains("MISSING header: build.ps1"), "missing log absent: {stderr}");
 }
 
+#[test]
+fn scanner_reports_missing_header_in_powershell_data_file() {
+    // Regression guard: `.psd1` must be classified as PowerShell so a
+    // missing header is reported (rather than the file being silently
+    // skipped, which was the pre-fix behaviour).
+    let dir = TempDir::new().unwrap();
+    let p = dir.path();
+    write(&p.join(".cargo-heather.toml"), CONFIG_MIT);
+    write(&p.join("Settings.psd1"), "@{ Name = 'Settings' }\n");
+
+    let out = run_heather(p, &[]);
+    let stderr = stderr_of(&out);
+    assert!(!out.status.success(), "missing .psd1 header should fail: {stderr}");
+    assert!(stderr.contains("MISSING header: Settings.psd1"), "missing log absent: {stderr}");
+}
+
+#[test]
+fn scanner_reports_missing_header_in_powershell_module_file() {
+    let dir = TempDir::new().unwrap();
+    let p = dir.path();
+    write(&p.join(".cargo-heather.toml"), CONFIG_MIT);
+    write(&p.join("Module.psm1"), "function Get-Foo { }\n");
+
+    let out = run_heather(p, &[]);
+    let stderr = stderr_of(&out);
+    assert!(!out.status.success(), "missing .psm1 header should fail: {stderr}");
+    assert!(stderr.contains("MISSING header: Module.psm1"), "missing log absent: {stderr}");
+}
+
 #[test]
 fn scanner_ignores_unsupported_extension_even_when_hash_comments_would_work() {
     let dir = TempDir::new().unwrap();