fix: allow empty result from changed vcs files (#1776)

Co-authored-by: Anthony Giniers <[email protected]>
Co-authored-by: Emanuele Stoppa <[email protected]>

CHANGELOG.md

@@ -149,6 +149,7 @@ our [guidelines for writing a good changelog entry](https://github.com/biomejs/b
 
   ```
   Contributed by @ematipico
+- Fix [#1774](https://github.com/biomejs/biome/issues/1774) by taking into account the option `--no-errors-on-unmatched` when running the CLI using `--changed`. Contributed by @antogyn
 
 #### Enhancements
 

crates/biome_cli/src/changed.rs

@@ -24,9 +24,5 @@ pub(crate) fn get_changed_files(
 
     let filtered_changed_files = changed_files.iter().map(OsString::from).collect::<Vec<_>>();
 
-    if filtered_changed_files.is_empty() {
-        return Err(CliDiagnostic::no_files_processed());
-    }
-
     Ok(filtered_changed_files)
 }

crates/biome_cli/src/execute/traverse.rs

@@ -143,7 +143,10 @@ pub(crate) fn traverse(
     inputs: Vec<OsString>,
 ) -> Result<(), CliDiagnostic> {
     init_thread_pool();
-    if inputs.is_empty() && execution.as_stdin_file().is_none() {
+    if inputs.is_empty()
+        && execution.as_stdin_file().is_none()
+        && !cli_options.no_errors_on_unmatched
+    {
         return Err(CliDiagnostic::missing_argument(
             "<INPUT>",
             format!("{}", execution.traversal_mode),

crates/biome_cli/tests/commands/lint.rs

@@ -2683,6 +2683,44 @@ fn should_not_process_ignored_file_even_if_its_changed() {
     ));
 }
 
+#[test]
+fn should_not_error_for_no_changed_files_with_no_errors_on_unmatched() {
+    let mut console = BufferConsole::default();
+    let mut fs = MemoryFileSystem::default();
+
+    let file_path = Path::new("file.js");
+    fs.insert(file_path.into(), r#"console.log('file');"#.as_bytes());
+
+    let file_path2 = Path::new("file2.js");
+    fs.insert(file_path2.into(), r#"console.log('file2');"#.as_bytes());
+
+    let result = run_cli(
+        DynRef::Borrowed(&mut fs),
+        &mut console,
+        Args::from(
+            [
+                ("lint"),
+                "--changed",
+                "--since=main",
+                "--no-errors-on-unmatched",
+                file_path.as_os_str().to_str().unwrap(),
+                file_path2.as_os_str().to_str().unwrap(),
+            ]
+            .as_slice(),
+        ),
+    );
+
+    assert!(result.is_ok(), "run_cli returned {result:?}");
+
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "should_not_error_for_no_changed_files_with_no_errors_on_unmatched",
+        fs,
+        console,
+        result,
+    ));
+}
+
 #[test]
 fn lint_syntax_rules() {
     let mut fs = MemoryFileSystem::default();

crates/biome_cli/tests/snapshots/main_commands_lint/should_not_error_for_no_changed_files_with_no_errors_on_unmatched.snap

@@ -0,0 +1,23 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: content
+---
+## `file.js`
+
+```js
+console.log('file');
+```
+
+## `file2.js`
+
+```js
+console.log('file2');
+```
+
+# Emitted Messages
+
+```block
+Checked 0 file(s) in <TIME>
+```
+
+

crates/biome_fs/src/fs/memory.rs

@@ -37,7 +37,9 @@ impl Default for MemoryFileSystem {
             files: Default::default(),
             errors: Default::default(),
             allow_write: true,
-            on_get_changed_files: None,
+            on_get_changed_files: Some(Arc::new(AssertUnwindSafe(Mutex::new(Some(Box::new(
+                || vec![],
+            )))))),
         }
     }
 }

website/src/content/docs/internals/changelog.md

@@ -155,6 +155,7 @@ our [guidelines for writing a good changelog entry](https://github.com/biomejs/b
 
   ```
   Contributed by @ematipico
+- Fix [#1774](https://github.com/biomejs/biome/issues/1774) by taking into account the option `--no-errors-on-unmatched` when running the CLI using `--changed`. Contributed by @antogyn
 
 #### Enhancements