Bug 637572 - Implement Debugger.Source.prototype.sourceStart/Length; r=jimb

js/src/jit-test/tests/debug/Script-sourceStart-01.js

@@ -0,0 +1,22 @@
+/*
+ * Script.prototype.sourceStart and Script.prototype.sourceLength should both be
+ * a number.
+ */
+let g = newGlobal('new-compartment');
+let dbg = new Debugger(g);
+
+var count = 0;
+function test(string, range) {
+    dbg.onNewScript = function (script) {
+        ++count;
+        assertEq(script.sourceStart, range[0]);
+        assertEq(script.sourceLength, range[1]);
+    };
+
+    g.eval(string);
+};
+
+test("", [0, 0]);
+test("2 * 3", [0, 5]);
+test("2\n*\n3", [0, 5]);
+assertEq(count, 3);

js/src/jit-test/tests/debug/Script-sourceStart-02.js

@@ -0,0 +1,32 @@
+/*
+ * For function statements, Script.prototype.sourceStart and
+ * Script.prototype.sourceLength should comprise both the opening '(' and the
+ * closing '}'.
+ */
+let g = newGlobal('new-compartment');
+let dbg = new Debugger(g);
+
+function test(string, ranges) {
+    var index = 0;
+    dbg.onNewScript = function (script) {
+        function traverse(script) {
+            script.getChildScripts().forEach(function (script) {
+                assertEq(script.sourceStart, ranges[index][0]);
+                assertEq(script.sourceLength, ranges[index][1]);
+                ++index;
+                traverse(script);
+            });
+        }
+        traverse(script);
+    };
+
+    g.eval(string);
+    assertEq(index, ranges.length);
+};
+
+test("function f() {}", [[10, 5]]);
+test("function f() { function g() {} }", [[10, 22], [25, 5]]);
+test("function f() { function g() { function h() {} } }", [[10, 39], [25, 22], [40, 5]]);
+test("function f() { if (true) function g() {} }", [[10, 32], [35, 5]]); 
+test("var o = { get p () {} }", [[16, 5]]);
+test("var o = { set p (x) {} }", [[16, 6]]);

js/src/jit-test/tests/debug/Script-sourceStart-03.js

@@ -0,0 +1,31 @@
+/*
+ * For arrow functions, Script.prototype.sourceStart and
+ * Script.prototype.sourceLength should comprise the entire function expression
+ * (including arguments)
+ */
+let g = newGlobal('new-compartment');
+let dbg = new Debugger(g);
+
+function test(string, ranges) {
+    var index = 0;
+    dbg.onNewScript = function (script) {
+        function traverse(script) {
+            script.getChildScripts().forEach(function (script) {
+                assertEq(script.sourceStart, ranges[index][0]);
+                assertEq(script.sourceLength, ranges[index][1]);
+                ++index;
+                traverse(script);
+            });
+        }
+        traverse(script);
+    };
+
+    g.eval(string);
+    assertEq(index, ranges.length);
+};
+
+test("() => {}", [[0, 8]]);
+test("(x, y) => { x * y }", [[0, 19]]);
+test("x => x * x", [[0, 10]]);
+test("x => x => x * x", [[0, 15], [5, 10]]);
+test("x => x => x => x * x", [[0, 20], [5, 15], [10, 10]]);

js/src/jit-test/tests/debug/Script-sourceStart-04.js

@@ -0,0 +1,25 @@
+/*
+ * For eval and Function constructors, Script.prototype.sourceStart and
+ * Script.prototype.sourceLength should comprise the entire script (excluding
+ * arguments in the case of Function constructors)
+ */
+let g = newGlobal('new-compartment');
+let dbg = new Debugger(g);
+
+var count = 0;
+function test(string, range) {
+    dbg.onNewScript = function (script) {
+        ++count;
+        if (count % 2 == 0) {
+            assertEq(script.sourceStart, range[0]);
+            assertEq(script.sourceLength, range[1]);
+        }
+    }
+
+    g.eval(string);
+}
+
+test("eval('2 * 3')", [0, 5]);
+test("new Function('2 * 3')", [0, 5]);
+test("new Function('x', 'x * x')", [0, 5]);
+assertEq(count, 6);

js/src/vm/Debugger.cpp

@@ -2848,6 +2848,22 @@ DebuggerScript_getSource(JSContext *cx, unsigned argc, Value *vp)
     return true;
 }
 
+static JSBool
+DebuggerScript_getSourceStart(JSContext *cx, unsigned argc, Value *vp)
+{
+    THIS_DEBUGSCRIPT_SCRIPT(cx, argc, vp, "(get sourceStart)", args, obj, script);
+    args.rval().setNumber(script->sourceStart);
+    return true;
+}
+
+static JSBool
+DebuggerScript_getSourceLength(JSContext *cx, unsigned argc, Value *vp)
+{
+    THIS_DEBUGSCRIPT_SCRIPT(cx, argc, vp, "(get sourceEnd)", args, obj, script);
+    args.rval().setNumber(script->sourceEnd - script->sourceStart);
+    return true;
+}
+
 static JSBool
 DebuggerScript_getStaticLevel(JSContext *cx, unsigned argc, Value *vp)
 {
@@ -3485,6 +3501,8 @@ static const JSPropertySpec DebuggerScript_properties[] = {
     JS_PSG("startLine", DebuggerScript_getStartLine, 0),
     JS_PSG("lineCount", DebuggerScript_getLineCount, 0),
     JS_PSG("source", DebuggerScript_getSource, 0),
+    JS_PSG("sourceStart", DebuggerScript_getSourceStart, 0),
+    JS_PSG("sourceLength", DebuggerScript_getSourceLength, 0),
     JS_PSG("staticLevel", DebuggerScript_getStaticLevel, 0),
     JS_PSG("sourceMapURL", DebuggerScript_getSourceMapUrl, 0),
     JS_PS_END