add tests and support for wasm stack frames

source-map-support.js

@@ -520,6 +520,12 @@ function wrapCallSite(frame, state) {
   // from getScriptNameOrSourceURL() instead
   var source = frame.getFileName() || frame.getScriptNameOrSourceURL();
   if (source) {
+    // v8 does not expose its internal isWasm, etc methods, so we do this instead.
+    if(source.startsWith('wasm://')) {
+      state.curPosition = null;
+      return frame;
+    }
+
     var line = frame.getLineNumber();
     var column = frame.getColumnNumber() - 1;
 

test-fixtures/wasm/README.md

@@ -0,0 +1,12 @@
+To test support for WASM stack traces, we have a tiny WASM module that we call
+into.
+
+It imports a JS function and exports a WASM function
+that, when called, will call the JS function.
+
+When we call the wasm function, it calls back into JS.  We can throw an error
+and know that one of the stack frames will be wasm.
+
+The module is described in both text and binary formats.  Compilation from text
+to binary format was done using an online tool.  I didn't bother to set up a
+build script, opting instead ot store the binary in version control.

test-fixtures/wasm/wasm.js

@@ -0,0 +1,14 @@
+const fs = require('fs');
+const path = require('path');
+
+exports.call_js_function = async function(fn) {
+  const mod = await WebAssembly.instantiate(
+    fs.readFileSync(path.resolve(__dirname, 'wasm.wasm')),
+    {
+      jsapi: {
+        fn
+      }
+    }
+  );
+  mod.instance.exports.call_js_function();
+}

test-fixtures/wasm/wasm.wat

@@ -0,0 +1,6 @@
+(module
+    (import "jsapi" "fn" (func $jsapi_fn))
+    (func (export "call_js_function")
+        call $jspapi_fn
+    )
+)

test.js

@@ -526,6 +526,17 @@ it('async stack frames: Promise.any', async function() {
   ]);
 });
 
+it('wasm stack frames', async function() {
+  await compareStackTrace(createMultiLineSourceMap(), [
+    'return require("./test-fixtures/wasm/wasm.js").call_js_function(() => { throw new Error("test"); });'
+  ], [
+    'Error: test',
+    re`^    at ${stackFramePathStartsWith()}(?:.*[/\\])?line1.js:1001:101$`,
+    re`^    at wasm:\/\/wasm\/c2de0ab2:wasm-function\[1\]:0x3b$`,
+    re`^    at Object\.exports\.call_js_function \(.*[/\\]wasm\.js:13:24\)$`,
+  ]);
+});
+
 it('throw with empty source map', async function() {
   await compareStackTrace(createEmptySourceMap(), [
     'throw new Error("test");'