1 files changed, 79 insertions, 0 deletions
diff --git a/js/src/jit-test/lib/assert-offset-columns.js b/js/src/jit-test/lib/assert-offset-columns.js
new file mode 100644
index 0000000000..6fb75ac74c
--- /dev/null
+++ b/js/src/jit-test/lib/assert-offset-columns.js
@@ -0,0 +1,79 @@
+// Set breakpoints "everywhere" in a function, then call the function and check that
+// the breakpoints were added are at the expected columns, and the breakpoints
+// were executed in th expected order.
+//
+// `code` is a JS Script. The final line should define a function `f` to validate.
+// `expectedBpts` is a string of spaces and carets ('^'). Throws if we don't hit
+// breakpoints on exactly the columns indicated by the carets.
+// `expectedOrdering` is a string of integer indices for the offsets that are
+// executed, in the order that then are executed. Test code can also push
+// additional items into this string using items.push("!").
+function assertOffsetColumns(code, expectedBpts, expectedOrdering = null) {
+    if (expectedOrdering === null) {
+        // The default ordering simply runs the breakpoints in order.
+        expectedOrdering = Array.from(expectedBpts.match(/\^/g), (_, i) => i).join(" ");
+    }
+
+    // Define the function `f` in a new global.
+    const global = newGlobal({newCompartment: true});
+
+    const lines = code.split(/\r?\n|\r]/g);
+    const initCode = lines.slice(0, -1).join("\n");
+    const execCode = lines[lines.length - 1];
+
+    // Treat everything but the last line as initialization code.
+    global.eval(initCode);
+
+    // Run the test code itself.
+    global.eval(execCode);
+
+    // Allow some tests to append to a log that will show up in expected ordering.
+    const hits = global.hits = [];
+    const bpts = new Set();
+
+    // Set breakpoints everywhere and call the function.
+    const dbg = new Debugger;
+    let debuggeeFn = dbg.addDebuggee(global).makeDebuggeeValue(global.f);
+    if (debuggeeFn.isBoundFunction) {
+        debuggeeFn = debuggeeFn.boundTargetFunction;
+    }
+
+    const { script } = debuggeeFn;
+    for (const offset of script.getAllColumnOffsets()) {
+        assertEq(offset.lineNumber, 1);
+        assertEq(offset.columnNumber < execCode.length, true);
+        bpts.add(offset.columnNumber);
+
+        script.setBreakpoint(offset.offset, {
+            hit(frame) {
+                hits.push(offset.columnNumber);
+            },
+        });
+    }
+    global.f(3);
+
+    const actualBpts = Array.from(execCode, (_, i) => {
+        return bpts.has(i) ? "^" : " ";
+    }).join("");
+
+    if (actualBpts.trimEnd() !== expectedBpts.trimEnd()) {
+        throw new Error(`Assertion failed:
+                     code: ${execCode}
+            expected bpts: ${expectedBpts}
+              actual bpts: ${actualBpts}\n`);
+    }
+
+    const indexLookup = new Map(
+        Array.from(bpts).sort().map((col, i) => [col, i]));
+    const actualOrdering = hits
+        .map(item => typeof item === "number" ? indexLookup.get(item) : item)
+        .join(" ");
+
+    if (actualOrdering.trimEnd() !== expectedOrdering.trimEnd()) {
+        throw new Error(`Assertion failed:
+                     code: ${execCode}
+                     bpts: ${expectedBpts}
+           expected order: ${expectedOrdering}
+             actual order: ${actualOrdering}\n`);
+    }
+}