oxc-project · graphite-app · Feb 8, 2026 · Feb 8, 2026
@@ -7,8 +7,8 @@
 | Status            | Count | %      |
 | ----------------- | ----- | ------ |
 | Total rules       |   292 | 100.0% |
-| Fully passing     |   286 |  97.9% |
-| Partially passing |     6 |   2.1% |
+| Fully passing     |   287 |  98.3% |
+| Partially passing |     5 |   1.7% |
 | Fully failing     |     0 |   0.0% |
 | Load errors       |     0 |   0.0% |
 | No tests run      |     0 |   0.0% |
@@ -18,8 +18,8 @@
 | Status      | Count | %      |
 | ----------- | ----- | ------ |
 | Total tests | 33159 | 100.0% |
-| Passing     | 32869 |  99.1% |
-| Failing     |    12 |   0.0% |
+| Passing     | 32871 |  99.1% |
+| Failing     |    10 |   0.0% |
 | Skipped     |   278 |   0.8% |
 
 ## Fully Passing Rules
@@ -303,6 +303,7 @@
 - `symbol-description` (8 tests)
 - `template-curly-spacing` (57 tests)
 - `template-tag-spacing` (63 tests)
+- `unicode-bom` (7 tests)
 - `use-isnan` (214 tests)
 - `valid-typeof` (54 tests)
 - `vars-on-top` (61 tests)
@@ -318,7 +319,6 @@
 - `no-unused-labels` - 23 / 26 (88.5%)
 - `object-curly-newline` - 143 / 144 (99.3%)
 - `space-in-parens` - 137 / 139 (98.6%)
-- `unicode-bom` - 5 / 7 (71.4%)
 
 ## Rules with Failures Detail
 
@@ -771,64 +771,3 @@ AssertionError [ERR_ASSERTION]: Output is incorrect
     at apps/oxlint/dist/plugins-dev.js
     at it (apps/oxlint/conformance/src/capture.ts:123:5)
 
-
-### `unicode-bom`
-
-Pass: 5 / 7 (71.4%)
-Fail: 2 / 7 (28.6%)
-Skip: 0 / 7 (0.0%)
-
-#### unicode-bom > invalid
-
-```js
- var a = 123;
-```
-
-```json
-{
-  "output": " var a = 123;",
-  "errors": [
-    {
-      "messageId": "unexpected",
-      "line": 1,
-      "column": 1
-    }
-  ]
-}
-```
-
-Error: Failed to apply fixes
-    at assertInvalidTestCasePasses (apps/oxlint/dist/plugins-dev.js)
-    at runInvalidTestCase (apps/oxlint/dist/plugins-dev.js)
-    at apps/oxlint/dist/plugins-dev.js
-    at it (apps/oxlint/conformance/src/capture.ts:123:5)
-
-
-#### unicode-bom > invalid
-
-```js
- var a = 123;
-```
-
-```json
-{
-  "output": " var a = 123;",
-  "options": [
-    "never"
-  ],
-  "errors": [
-    {
-      "messageId": "unexpected",
-      "line": 1,
-      "column": 1
-    }
-  ]
-}
-```
-
-Error: Failed to apply fixes
-    at assertInvalidTestCasePasses (apps/oxlint/dist/plugins-dev.js)
-    at runInvalidTestCase (apps/oxlint/dist/plugins-dev.js)
-    at apps/oxlint/dist/plugins-dev.js
-    at it (apps/oxlint/conformance/src/capture.ts:123:5)
-
@@ -34,6 +34,9 @@ export declare const enum Severity {
  *    one group per diagnostic which provides fixes.
  *    Each inner array should have length of 1 at minimum.
  *
+ * If source text starts with a BOM, `JSFix`es must have offsets relative to the start
+ * of the source text *without* the BOM.
+ *
  * Each group's fixes are merged, then all merged fixes are applied to `source_text`.
  *
  * Fix ranges are converted from UTF-16 code units to UTF-8 bytes.

@@ -18,6 +18,12 @@ export type FixFn = (
 
 /**
  * Fix, as returned by `fix` function.
+ *
+ * `range` offsets are relative to start of the source text.
+ * When the file has a BOM, they are relative to the start of the source text *without* the BOM.
+ *
+ * To represent a position *before* a BOM, -1 is used to mean "before the BOM".
+ * ESLint's `unicode-bom` rule produces a fix `{ range: [-1, 0], text: "" }` to remove a BOM.
  */
 export interface Fix {
   range: Range;
@@ -26,10 +32,19 @@ export interface Fix {
 
 /**
  * Fix, in form sent to Rust.
+ *
+ * Offsets have 1 added to them, so that -1 in `Fix`'s `range` is represented as 0 in `FixReport`.
+ * This means that both `startPlusOne` and `endPlusOne` are valid `u32`s, even if original range elements were -1.
+ *
+ * `Fix { range: [0, 10], text: "xxx" }` -> `FixReport { startPlusOne: 1, endPlusOne: 11, text: "xxx" }`.
+ * `Fix { range: [-1, 0], text: "" }` -> `FixReport { startPlusOne: 0, endPlusOne: 1, text: "" }`.
+ *
+ * Range offsets can be -1 when the file has a BOM, and the fix starts before the BOM.
+ * ESLint's `unicode-bom` rule produces a fix `{ range: [-1, 0], text: "" }` to remove a BOM.
  */
 export interface FixReport {
-  start: number;
-  end: number;
+  startPlusOne: number;
+  endPlusOne: number;
   text: string;
 }
 
@@ -223,8 +238,11 @@ function validateAndConvertFix(fix: Fix): FixReport {
     const start = range[0],
       end = range[1];
     if (typeof start === "number" && typeof end === "number") {
-      // Converting `text` to string follows ESLint, which does that implicitly
-      return { start, end, text: String(text) };
+      // Add 1 to `start` and `end`, to allow original offsets to be -1 (meaning "before the BOM"),
+      // and `FixReport`'s `startPlusOne` and `endPlusOne` are still valid `u32`s on Rust side.
+      //
+      // Converting `text` to string follows ESLint, which does that implicitly.
+      return { startPlusOne: start + 1, endPlusOne: end + 1, text: String(text) };
     }
   }
 

@@ -4,13 +4,20 @@ use oxc_ast_visit::utf8_to_utf16::Utf8ToUtf16;
 use oxc_diagnostics::OxcDiagnostic;
 use oxc_linter::{Fixer, JsFix, Message, PossibleFixes, convert_and_merge_js_fixes};
 
+const BOM: &str = "\u{feff}";
+#[expect(clippy::cast_possible_truncation)]
+const BOM_LEN: u32 = BOM.len() as u32;
+
 /// Apply fixes to source text and return the fixed code.
 ///
 /// - `source_text` is the original source code.
 /// - `fixes_json` is a JSON string containing `Vec<Vec<JsFix>>` — an array of fix groups,
 ///    one group per diagnostic which provides fixes.
 ///    Each inner array should have length of 1 at minimum.
 ///
+/// If source text starts with a BOM, `JSFix`es must have offsets relative to the start
+/// of the source text *without* the BOM.
+///
 /// Each group's fixes are merged, then all merged fixes are applied to `source_text`.
 ///
 /// Fix ranges are converted from UTF-16 code units to UTF-8 bytes.
@@ -20,14 +27,20 @@ pub fn apply_fixes(source_text: String, fixes_json: String) -> Option<String> {
     // Deserialize fixes JSON
     let fix_groups: Vec<Vec<JsFix>> = serde_json::from_str(&fixes_json).ok()?;
 
-    // Create `Utf8ToUtf16` converter
-    let span_converter = Utf8ToUtf16::new(&source_text);
+    // Create `Utf8ToUtf16` converter.
+    // If file has a BOM, trim it off start of the source text before creating the converter.
+    let has_bom = source_text.starts_with(BOM);
+    let span_converter = if has_bom {
+        Utf8ToUtf16::new_with_offset(&source_text[BOM_LEN as usize..], BOM_LEN)
+    } else {
+        Utf8ToUtf16::new(&source_text)
+    };
 
     // Merge fix groups into a single fix per group
     let messages = fix_groups
         .into_iter()
         .map(|group| {
-            convert_and_merge_js_fixes(group, &source_text, &span_converter)
+            convert_and_merge_js_fixes(group, &source_text, &span_converter, has_bom)
                 .ok()
                 .map(|fix| Message::new(OxcDiagnostic::error(""), PossibleFixes::Single(fix)))
         })

@@ -0,0 +1,2 @@
+a = c;
+d = b
@@ -0,0 +1,2 @@
+a = c;
+d = b
@@ -5,7 +5,7 @@
 ```
   x Error running JS plugin.
   | File path: <fixture>/files/range_end_negative.js
-  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `-10`, expected u32 at line 1 column 116
+  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `-9`, expected u32 at line 1 column 129
 
   x Plugin `fixes-plugin/fixes` returned invalid fixes.
   | File path: <fixture>/files/range_end_out_of_bounds.js
@@ -17,7 +17,7 @@
 
   x Error running JS plugin.
   | File path: <fixture>/files/range_end_too_large.js
-  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `4294967296`, expected u32 at line 1 column 124
+  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `4294967297`, expected u32 at line 1 column 138
 
   x Plugin `fixes-plugin/fixes` returned invalid fixes.
   | File path: <fixture>/files/range_start_after_end.js
@@ -29,11 +29,11 @@
 
   x Error running JS plugin.
   | File path: <fixture>/files/range_start_negative.js
-  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `-10`, expected u32 at line 1 column 110
+  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `-9`, expected u32 at line 1 column 116
 
   x Error running JS plugin.
   | File path: <fixture>/files/range_start_too_large.js
-  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `4294967296`, expected u32 at line 1 column 118
+  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `4294967297`, expected u32 at line 1 column 125
 
   x fixes-plugin(fixes): end out of bounds
    ,-[files/range_end_out_of_bounds.js:1:5]
@@ -60,7 +60,7 @@
    `----
 
 Found 0 warnings and 12 errors.
-Finished in Xms on 10 files with 1 rules using X threads.
+Finished in Xms on 12 files with 1 rules using X threads.
 ```
 
 # stderr
@@ -80,6 +80,18 @@ rage = abacus
 rage = abacus
 ```
 
+# File altered: files/bom_remove.js
+```
+daddy = magic;
+damned = abacus
+```
+
+# File altered: files/bom_remove2.js
+```
+daddy = magic;
+damned = abacus
+```
+
 # File altered: files/index.js
 ```
 

@@ -5,7 +5,7 @@
 ```
   x Error running JS plugin.
   | File path: <fixture>/files/range_end_negative.js
-  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `-10`, expected u32 at line 1 column 116
+  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `-9`, expected u32 at line 1 column 129
 
   x Plugin `fixes-plugin/fixes` returned invalid fixes.
   | File path: <fixture>/files/range_end_out_of_bounds.js
@@ -17,7 +17,7 @@
 
   x Error running JS plugin.
   | File path: <fixture>/files/range_end_too_large.js
-  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `4294967296`, expected u32 at line 1 column 124
+  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `4294967297`, expected u32 at line 1 column 138
 
   x Plugin `fixes-plugin/fixes` returned invalid fixes.
   | File path: <fixture>/files/range_start_after_end.js
@@ -29,11 +29,11 @@
 
   x Error running JS plugin.
   | File path: <fixture>/files/range_start_negative.js
-  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `-10`, expected u32 at line 1 column 110
+  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `-9`, expected u32 at line 1 column 116
 
   x Error running JS plugin.
   | File path: <fixture>/files/range_start_too_large.js
-  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `4294967296`, expected u32 at line 1 column 118
+  | Failed to deserialize JSON returned by `lintFile`: invalid value: integer `4294967297`, expected u32 at line 1 column 125
 
   x fixes-plugin(fixes): Replace "a" with "daddy"
    ,-[files/bom.js:1:4]
@@ -91,6 +91,74 @@
    :     ^
    `----
 
+  x fixes-plugin(fixes): Replace "a" with "daddy"
+   ,-[files/bom_remove.js:1:4]
+ 1 | a = c;
+   : ^
+ 2 | d = b
+   `----
+
+  x fixes-plugin(fixes): Remove BOM
+   ,-[files/bom_remove.js:1:4]
+ 1 | ,-> a = c;
+ 2 | `-> d = b
+   `----
+
+  x fixes-plugin(fixes): Prefix "c" with "magi"
+   ,-[files/bom_remove.js:1:8]
+ 1 | a = c;
+   :     ^
+ 2 | d = b
+   `----
+
+  x fixes-plugin(fixes): Prefix "d" with "damne"
+   ,-[files/bom_remove.js:2:1]
+ 1 | a = c;
+ 2 | d = b
+   : ^
+   `----
+
+  x fixes-plugin(fixes): Replace "b" with "abacus"
+   ,-[files/bom_remove.js:2:5]
+ 1 | a = c;
+ 2 | d = b
+   :     ^
+   `----
+
+  x fixes-plugin(fixes): Replace "a" with "daddy"
+   ,-[files/bom_remove2.js:1:4]
+ 1 | a = c;
+   : ^
+ 2 | d = b
+   `----
+
+  x fixes-plugin(fixes): Remove BOM multiple
+   ,-[files/bom_remove2.js:1:4]
+ 1 | ,-> a = c;
+ 2 | `-> d = b
+   `----
+
+  x fixes-plugin(fixes): Prefix "c" with "magi"
+   ,-[files/bom_remove2.js:1:8]
+ 1 | a = c;
+   :     ^
+ 2 | d = b
+   `----
+
+  x fixes-plugin(fixes): Prefix "d" with "damne"
+   ,-[files/bom_remove2.js:2:1]
+ 1 | a = c;
+ 2 | d = b
+   : ^
+   `----
+
+  x fixes-plugin(fixes): Replace "b" with "abacus"
+   ,-[files/bom_remove2.js:2:5]
+ 1 | a = c;
+ 2 | d = b
+   :     ^
+   `----
+
   x fixes-plugin(fixes): Remove debugger statement
    ,-[files/index.js:1:1]
  1 | debugger;
@@ -237,8 +305,8 @@
    :     ^
    `----
 
-Found 0 warnings and 36 errors.
-Finished in Xms on 10 files with 1 rules using X threads.
+Found 0 warnings and 46 errors.
+Finished in Xms on 12 files with 1 rules using X threads.
 ```
 
 # stderr