fix: Improve our console.log output for functions

We now log out the function's source, unless it is native code, and then we replace the function body with the text '[native code]'

Author: Jake Champion

integration-tests/js-compute/fixtures/app/src/console.js

@@ -14,7 +14,7 @@ routes.set("/console", () => {
     console.log('Set:',arg)
     arg = [1, 2, 3, [], 5]
     console.log('Array:',arg)
-    arg = { a: 1, b: 2, c: 3, d(){}, get f(){return 1}, g: function bar() {} }
+    arg = { a: 1, b: 2, c: 3, d(){}, get f(){return 1}, g: function bar() {}, h: Array.from }
     console.log('Object:',arg)
     arg = function () { }
     console.log('function:',arg)

integration-tests/js-compute/fixtures/app/tests.json

@@ -1043,19 +1043,19 @@
     },
     "logs": [
       "stdout :: Log: Happy birthday Aki and Yuki!",
-      "stdout :: Log: Map: Map(2) { { a: 1, b: { c: 2 } } => 2, [Function foo] => {} }",
+      "stdout :: Log: Map: Map(2) { { a: 1, b: { c: 2 } } => 2, [ function foo() {\n    }] => {} }",
       "stdout :: Log: Set: Set(3) { { a: 1, b: { c: 2 } }, 2, 3 }",
       "stdout :: Log: Array: [1, 2, 3, [], 5]",
-      "stdout :: Log: Object: { a: 1, b: 2, c: 3, d: [Function d], f: [Getter], g: [Function bar] }",
-      "stdout :: Log: function: [Function]",
+      "stdout :: Log: Object: { a: 1, b: 2, c: 3, d: [ d() {\n    }], f: [Getter], g: [ function bar() {\n}], h: [ function from() {\n[native code]\n}] }",
+      "stdout :: Log: function: [ function() {\n    }]",
       "stdout :: Log: boolean: true",
       "stdout :: Log: undefined: undefined",
       "stdout :: Log: null: null",
       "stdout :: Log: proxy: { a: 21 }",
       "stdout :: Log: Infinity: Infinity",
       "stdout :: Log: NaN: NaN",
       "stdout :: Log: Symbol: Symbol(\"wow\")",
-      "stdout :: Log: Error: (new Error(\"uh oh\", \"<stdin>\", 40))",
+      "stdout :: Log: Error: (new Error(\"uh oh\", \"<stdin>\", 7644))",
       "stdout :: Log: Number: 1",
       "stdout :: Log: Number: 1.111",
       "stdout :: Log: BigInt: 10n",
@@ -1077,9 +1077,9 @@
       "stdout :: Log: WeakSet: WeakSet { <items unknown> }",
       "stdout :: Log: Promise: Promise { <pending> }",
       "stdout :: Log: resolved promise: Promise { 9 }",
-      "stdout :: Log: rejected promise: Promise { <rejected> (new Error(\"oops\", \"<stdin>\", 85)) }",
+      "stdout :: Log: rejected promise: Promise { <rejected> (new Error(\"oops\", \"<stdin>\", 7689)) }",
       "stdout :: Log: Response: Response { redirected: false, type: \"default\", url: \"\", status: 200, ok: true, statusText: \"\", version: 2, headers: Headers {}, body: ReadableStream { locked: false }, bodyUsed: false }",
-      "stdout :: Log: Request: Request { method: \"POST\", url: \"https://www.fastly.com/\", version: 2, headers: Headers {}, body: null, bodyUsed: false }",
+      "stdout :: Log: Request: Request { method: \"POST\", url: \"https://www.fastly.com/\", version: 2, headers: Headers {}, backend: undefined, body: null, bodyUsed: false }",
       "stdout :: Log: ReadableStream: ReadableStream { locked: false }",
       "stdout :: Log: TransformStream: TransformStream { readable: ReadableStream { locked: false }, writable: WritableStream {} }",
       "stdout :: Log: WritableStream: WritableStream {}",

runtime/js-compute-runtime/builtins/shared/console.cpp

@@ -286,19 +286,16 @@ JS::Result<mozilla::Ok> ToSource(JSContext *cx, std::string &sourceOut, JS::Hand
     JS::RootedObject obj(cx, &val.toObject());
 
     if (JS_ObjectIsFunction(obj)) {
-      sourceOut += "[Function";
+      sourceOut += "[";
       std::string source;
       JS::Rooted<JSFunction *> fun(cx, JS_ValueToFunction(cx, val));
       if (fun) {
-        JS::RootedString name(cx);
-        if (!JS_GetFunctionId(cx, fun, &name)) {
+        JS::RootedString result(cx, JS_DecompileFunction(cx, fun));
+        if (!result) {
           return JS::Result<mozilla::Ok>(JS::Error());
         }
-        if (!name) {
-          name = JS_AtomizeAndPinString(cx, "");
-        }
         sourceOut += " ";
-        auto msg = core::encode(cx, name);
+        auto msg = core::encode(cx, result);
         if (!msg) {
           return JS::Result<mozilla::Ok>(JS::Error());
         }