1 files changed, 46 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Source-reparse.js b/js/src/jit-test/tests/debug/Source-reparse.js
new file mode 100644
index 0000000000..e12244d48f
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Source-reparse.js
@@ -0,0 +1,46 @@
+// reparsing a source should produce equivalent scripts and avoid invoking the
+// onNewScript hook.
+
+const g = newGlobal({newCompartment: true});
+const dbg = new Debugger;
+dbg.addDebuggee(g);
+
+let globalScript;
+dbg.onNewScript = script => { globalScript = script };
+
+// Leave `g()` on the first line so we can check that `columnNumber` is passed to the
+// reparsed script (`columnNumber` is only used to offset breakpoint column on the first
+// line of the script).
+g.evaluate(`g();
+function f() {
+  for (var i = 0; i < 10; i++) {
+    g();
+  }
+}
+
+function g() {
+  return 3;
+}
+
+f();
+`, { fileName: "foobar.js", lineNumber: 3, columnNumber: 42 });
+
+let onNewScriptCalls = 0;
+dbg.onNewScript = script => { onNewScriptCalls++; };
+
+const reparsedScript = globalScript.source.reparse();
+
+assertEq(onNewScriptCalls, 0);
+
+assertEq(reparsedScript.url, "foobar.js");
+assertEq(reparsedScript.startLine, 3);
+assertEq(reparsedScript.startColumn, 42);
+
+// Test for the same breakpoint positions in the original and reparsed script.
+function getBreakpointPositions(script) {
+  const offsets = script.getPossibleBreakpoints();
+  const str = offsets.map(({ lineNumber, columnNumber }) => `${lineNumber}:${columnNumber}`).toString();
+  const childPositions = script.getChildScripts().map(getBreakpointPositions);
+  return str + childPositions.toString();
+}
+assertEq(getBreakpointPositions(globalScript), getBreakpointPositions(reparsedScript));