fix(JSHandle.toString): clearer description for primitives (#993)

This patch:
- updates JSHandle.toString to make a nicer description for primitives
- excludes JSHandle.toString from documentation to avoid its abuse

References #382

docs/api.md

@@ -134,7 +134,6 @@
     + [jsHandle.getProperties()](#jshandlegetproperties)
     + [jsHandle.getProperty(propertyName)](#jshandlegetpropertypropertyname)
     + [jsHandle.jsonValue()](#jshandlejsonvalue)
-    + [jsHandle.toString()](#jshandletostring)
   * [class: ElementHandle](#class-elementhandle)
     + [elementHandle.asElement()](#elementhandleaselement)
     + [elementHandle.boundingBox()](#elementhandleboundingbox)
@@ -1509,9 +1508,6 @@ Returns a JSON representation of the object. The JSON is generated by running [`
 
 > **NOTE** The method will throw if the referenced object is not stringifiable.
 
-#### jsHandle.toString()
-- returns: <[string]>
-
 ### class: ElementHandle
 
 > **NOTE** Class [ElementHandle] extends [JSHandle].

lib/ExecutionContext.js

@@ -184,7 +184,7 @@ class JSHandle {
       const type =  this._remoteObject.subtype || this._remoteObject.type;
       return 'JSHandle@' + type;
     }
-    return helper.valueFromRemoteObject(this._remoteObject) + '';
+    return 'JSHandle:' + helper.valueFromRemoteObject(this._remoteObject);
   }
 }
 

lib/Page.js

@@ -330,8 +330,15 @@ class Page extends EventEmitter {
       return;
     }
     const values = event.args.map(arg => this._frameManager.createJSHandle(event.executionContextId, arg));
-    const text = values.join(' ');
-    const message = new ConsoleMessage(event.type, text, values);
+    const textTokens = [];
+    for (let i = 0; i < event.args.length; ++i) {
+      const remoteObject = event.args[i];
+      if (remoteObject.objectId)
+        textTokens.push(values[i].toString());
+      else
+        textTokens.push(helper.valueFromRemoteObject(remoteObject));
+    }
+    const message = new ConsoleMessage(event.type, textTokens.join(' '), values);
     this.emit(Page.Events.Console, message);
   }
 

test/test.js

@@ -408,8 +408,10 @@ describe('Page', function() {
 
   describe('JSHandle.toString', function() {
     it('should work for primitives', SX(async function() {
-      const aHandle = await page.evaluateHandle(() => 2);
-      expect(aHandle.toString()).toBe('2');
+      const numberHandle = await page.evaluateHandle(() => 2);
+      expect(numberHandle.toString()).toBe('JSHandle:2');
+      const stringHandle = await page.evaluateHandle(() => 'a');
+      expect(stringHandle.toString()).toBe('JSHandle:a');
     }));
     it('should work for complicated objects', SX(async function() {
       const aHandle = await page.evaluateHandle(() => window);

utils/doclint/check_public_api/index.js

@@ -37,6 +37,7 @@ const EXCLUDE_CLASSES = new Set([
 const EXCLUDE_METHODS = new Set([
   'Headers.fromPayload',
   'Page.create',
+  'JSHandle.toString',
 ]);
 
 /**