Try to fix end-of-region mapping

peggyjs · Jun 3, 2022 · febd2e9 · febd2e9
1 parent 4637045
commit febd2e9
Showing 1 changed file with 31 additions and 21 deletions.
diff --git a/lib/compiler/passes/generate-js.js b/lib/compiler/passes/generate-js.js
@@ -318,6 +318,26 @@ function generateJS(ast, options) {
       const sourceMapStack = [];
       let value;
 
+      function sourceMapPop() {
+        const [
+          index,
+          location,
+        ] = sourceMapStack.pop();
+        const chunks = parts.splice(index).map(
+          chunk => chunk instanceof SourceNode
+            ? chunk
+            : chunk + "\n"
+        );
+        if (chunks.length) {
+          parts.push(new SourceNode(
+            location.start.line,
+            location.start.column - 1,
+            location.source,
+            chunks
+          ));
+        }
+        return location;
+      }
       function compileCondition(cond, argCount) {
         const baseLength = argCount + 3;
         const thenLength = bc[ip + baseLength - 2];
@@ -587,27 +607,17 @@ function generateJS(ast, options) {
             break;
 
           case op.SOURCE_MAP_POP: {
-            const [
-              index,
-              location,
-            ] = sourceMapStack.pop();
-            const chunks = parts.splice(index).map(
-              chunk => chunk instanceof SourceNode
-                ? chunk
-                : chunk + "\n"
-            );
-            chunks.push(new SourceNode(
-              location.end.line,
-              location.end.column - 1,
-              location.source,
-              ""
-            ));
-            parts.push(new SourceNode(
-              location.start.line,
-              location.start.column - 1,
-              location.source,
-              chunks
-            ));
+            const location = sourceMapPop();
+            if (sourceMapStack.length
+              && location.end.offset
+              < sourceMapStack[sourceMapStack.length - 1][1].end.offset) {
+              const outer = sourceMapPop();
+              outer.start = location.end;
+              sourceMapStack.push([
+                parts.length,
+                outer,
+              ]);
+            }
             ip++;
             break;
           }