Add ignoreList support

package.json

@@ -69,7 +69,7 @@
     "typescript": "4.6.3"
   },
   "dependencies": {
-    "@jridgewell/gen-mapping": "^0.3.0",
-    "@jridgewell/trace-mapping": "^0.3.9"
+    "@jridgewell/gen-mapping": "^0.3.5",
+    "@jridgewell/trace-mapping": "^0.3.24"
   }
 }

src/build-source-map-tree.ts

@@ -50,7 +50,7 @@ function build(
   importer: string,
   importerDepth: number
 ): MapSourceType {
-  const { resolvedSources, sourcesContent } = map;
+  const { resolvedSources, sourcesContent, ignoreList } = map;
 
   const depth = importerDepth + 1;
   const children = resolvedSources.map((sourceFile: string | null, i: number): Sources => {
@@ -63,24 +63,26 @@ function build(
       depth,
       source: sourceFile || '',
       content: undefined,
+      ignore: undefined,
     };
 
     // Use the provided loader callback to retrieve the file's sourcemap.
     // TODO: We should eventually support async loading of sourcemap files.
     const sourceMap = loader(ctx.source, ctx);
 
-    const { source, content } = ctx;
+    const { source, content, ignore } = ctx;
 
     // If there is a sourcemap, then we need to recurse into it to load its source files.
     if (sourceMap) return build(new TraceMap(sourceMap, source), loader, source, depth);
 
-    // Else, it's an an unmodified source file.
+    // Else, it's an unmodified source file.
     // The contents of this unmodified source file can be overridden via the loader context,
     // allowing it to be explicitly null or a string. If it remains undefined, we fall back to
     // the importing sourcemap's `sourcesContent` field.
     const sourceContent =
       content !== undefined ? content : sourcesContent ? sourcesContent[i] : null;
-    return OriginalSource(source, sourceContent);
+    const ignored = ignore !== undefined ? ignore : ignoreList ? ignoreList.includes(i) : false;
+    return OriginalSource(source, sourceContent, ignored);
   });
 
   return MapSource(map, children);

src/source-map-tree.ts

@@ -1,4 +1,4 @@
-import { GenMapping, maybeAddSegment, setSourceContent } from '@jridgewell/gen-mapping';
+import { GenMapping, maybeAddSegment, setIgnore, setSourceContent } from '@jridgewell/gen-mapping';
 import { traceSegment, decodedMappings } from '@jridgewell/trace-mapping';
 
 import type { TraceMap } from '@jridgewell/trace-mapping';
@@ -9,55 +9,68 @@ export type SourceMapSegmentObject = {
   name: string;
   source: string;
   content: string | null;
+  ignore: boolean;
 };
 
 export type OriginalSource = {
   map: null;
   sources: Sources[];
   source: string;
   content: string | null;
+  ignore: boolean;
 };
 
 export type MapSource = {
   map: TraceMap;
   sources: Sources[];
   source: string;
   content: null;
+  ignore: false;
 };
 
 export type Sources = OriginalSource | MapSource;
 
-const SOURCELESS_MAPPING = /* #__PURE__ */ SegmentObject('', -1, -1, '', null);
+const SOURCELESS_MAPPING = /* #__PURE__ */ SegmentObject('', -1, -1, '', null, false);
 const EMPTY_SOURCES: Sources[] = [];
 
 function SegmentObject(
   source: string,
   line: number,
   column: number,
   name: string,
-  content: string | null
+  content: string | null,
+  ignore: boolean
 ): SourceMapSegmentObject {
-  return { source, line, column, name, content };
+  return { source, line, column, name, content, ignore };
 }
 
-function Source(map: TraceMap, sources: Sources[], source: '', content: null): MapSource;
+function Source(
+  map: TraceMap,
+  sources: Sources[],
+  source: '',
+  content: null,
+  ignore: false
+): MapSource;
 function Source(
   map: null,
   sources: Sources[],
   source: string,
-  content: string | null
+  content: string | null,
+  ignore: boolean
 ): OriginalSource;
 function Source(
   map: TraceMap | null,
   sources: Sources[],
   source: string | '',
-  content: string | null
+  content: string | null,
+  ignore: boolean
 ): Sources {
   return {
     map,
     sources,
     source,
     content,
+    ignore,
   } as any;
 }
 
@@ -66,15 +79,19 @@ function Source(
  * (which may themselves be SourceMapTrees).
  */
 export function MapSource(map: TraceMap, sources: Sources[]): MapSource {
-  return Source(map, sources, '', null);
+  return Source(map, sources, '', null, false);
 }
 
 /**
  * A "leaf" node in the sourcemap tree, representing an original, unmodified source file. Recursive
  * segment tracing ends at the `OriginalSource`.
  */
-export function OriginalSource(source: string, content: string | null): OriginalSource {
-  return Source(null, EMPTY_SOURCES, source, content);
+export function OriginalSource(
+  source: string,
+  content: string | null,
+  ignore: boolean
+): OriginalSource {
+  return Source(null, EMPTY_SOURCES, source, content, ignore);
 }
 
 /**
@@ -113,10 +130,11 @@ export function traceMappings(tree: MapSource): GenMapping {
         if (traced == null) continue;
       }
 
-      const { column, line, name, content, source } = traced;
+      const { column, line, name, content, source, ignore } = traced;
 
       maybeAddSegment(gen, i, genCol, source, line, column, name);
       if (source && content != null) setSourceContent(gen, source, content);
+      if (ignore) setIgnore(gen, source, true);
     }
   }
 
@@ -134,7 +152,7 @@ export function originalPositionFor(
   name: string
 ): SourceMapSegmentObject | null {
   if (!source.map) {
-    return SegmentObject(source.source, line, column, name, source.content);
+    return SegmentObject(source.source, line, column, name, source.content, source.ignore);
   }
 
   const segment = traceSegment(source.map, line, column);

src/source-map.ts

@@ -15,14 +15,15 @@ export default class SourceMap {
   declare sources: (string | null)[];
   declare sourcesContent?: (string | null)[];
   declare version: 3;
+  declare ignoreList: number[] | undefined;
 
   constructor(map: GenMapping, options: Options) {
     const out = options.decodedMappings ? toDecodedMap(map) : toEncodedMap(map);
     this.version = out.version; // SourceMap spec says this should be first.
     this.file = out.file;
     this.mappings = out.mappings as SourceMap['mappings'];
     this.names = out.names as SourceMap['names'];
-
+    this.ignoreList = out.ignoreList as SourceMap['ignoreList'];
     this.sourceRoot = out.sourceRoot;
 
     this.sources = out.sources as SourceMap['sources'];

src/types.ts

@@ -13,6 +13,7 @@ export type LoaderContext = {
   readonly depth: number;
   source: string;
   content: string | null | undefined;
+  ignore: boolean | undefined;
 };
 
 export type SourceMapLoader = (