Avoid throwing JSON parsing errors for non-JSON source maps

ai · ai · commit aaec7b78b3ce · 2026-04-26T13:09:20.000Z
diff --git a/lib/previous-map.js b/lib/previous-map.js
@@ -30,7 +30,7 @@ class PreviousMap {
 
   consumer() {
     if (!this.consumerCache) {
-      this.consumerCache = new SourceMapConsumer(this.text)
+      this.consumerCache = new SourceMapConsumer(this.json ?? this.text)
     }
     return this.consumerCache
   }
@@ -124,7 +124,15 @@ class PreviousMap {
     } else if (this.annotation) {
       let map = this.annotation
       if (file) map = join(dirname(file), map)
-      return this.loadFile(map)
+      let unknown = this.loadFile(map)
+      if (unknown) {
+        try {
+          this.json = JSON.parse(unknown.replace(/^\)]}'[^\n]*\n/, ''))
+        } catch (e) {
+          return undefined
+        }
+      }
+      return unknown
     }
   }
 

Original file line number	Diff line number	Diff line change
`@@ -30,7 +30,7 @@ class PreviousMap {`
`30`	`30`
`31`	`31`	`consumer() {`
`32`	`32`	`if (!this.consumerCache) {`
`33`		`- this.consumerCache = new SourceMapConsumer(this.text)`
	`33`	`+ this.consumerCache = new SourceMapConsumer(this.json ?? this.text)`
`34`	`34`	`}`
`35`	`35`	`return this.consumerCache`
`36`	`36`	`}`
`@@ -124,7 +124,15 @@ class PreviousMap {`
`124`	`124`	`} else if (this.annotation) {`
`125`	`125`	`let map = this.annotation`
`126`	`126`	`if (file) map = join(dirname(file), map)`
`127`		`- return this.loadFile(map)`
	`127`	`+ let unknown = this.loadFile(map)`
	`128`	`+ if (unknown) {`
	`129`	`+ try {`
	`130`	`+ this.json = JSON.parse(unknown.replace(/^\)]}'[^\n]*\n/, ''))`
	`131`	`+ } catch (e) {`
	`132`	`+ return undefined`
	`133`	`+ }`
	`134`	`+ }`
	`135`	`+ return unknown`
`128`	`136`	`}`
`129`	`137`	`}`
`130`	`138`