1 files changed, 68 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/class/default-constructor-position.js b/js/src/jit-test/tests/class/default-constructor-position.js
new file mode 100644
index 0000000000..abe2eeb7ab
--- /dev/null
+++ b/js/src/jit-test/tests/class/default-constructor-position.js
@@ -0,0 +1,68 @@
+// Test default class constructors have reasonable lineno/column values
+
+const source = `
+  /* GeneralParser::synthesizeConstructor */ class A {
+  }
+
+  /* GeneralParser::synthesizeConstructor (derived) */ class B extends A {
+  }
+
+  /* GeneralParser::synthesizeConstructor */ class C {
+    field = "default value";
+  }
+
+  /* GeneralParser::synthesizeConstructor (derived) */ class D extends A {
+    field = "default value";
+  }
+`;
+
+// Use the Debugger API to introspect the line / column.
+let d = new Debugger();
+let g = newGlobal({newCompartment: true})
+let gw = d.addDebuggee(g);
+
+g.evaluate(source);
+
+function getStartLine(name) {
+  return gw.makeDebuggeeValue(g.eval(name)).script.startLine;
+}
+
+function getStartColumn(name) {
+  return gw.makeDebuggeeValue(g.eval(name)).script.startColumn;
+}
+
+function getSourceStart(name) {
+  return gw.makeDebuggeeValue(g.eval(name)).script.sourceStart;
+}
+
+function getSourceLength(name) {
+  return gw.makeDebuggeeValue(g.eval(name)).script.sourceLength;
+}
+
+// Compute the expected line/column from source.
+matches = "";
+lineno = 0;
+for (text of source.split("\n")) {
+  lineno++;
+
+  column = text.indexOf("class");
+  if (column < 0) {
+    continue;
+  }
+
+  className = text[column + 6];
+  matches += className;
+
+  // Check lineno/column.
+  assertEq(getStartLine(className), lineno);
+  assertEq(getStartColumn(className), column);
+
+  // Check sourceStart/sourceEnd.
+  offset = source.indexOf("class " + className)
+  length = source.substring(offset).indexOf("}") + 1
+  assertEq(getSourceStart(className), offset)
+  assertEq(getSourceLength(className), length)
+}
+
+// Sanity check to did actual matches
+assertEq(matches, "ABCD");