fix(@angular/cli): sync lint error code behavior with TSLint

Author: clydin

packages/@angular/cli/tasks/lint.ts

@@ -98,10 +98,24 @@ export default Task.extend({
         if (current.fixes) {
           total.fixes = (total.fixes || []).concat(...current.fixes);
         }
+
+        if (current.errorCount !== undefined) {
+          total.errorCount += current.errorCount;
+        } else {
+          // Handle pre-warning/error bifurcation
+          total.errorCount += failures.length;
+        }
+
+        if (current.warningCount !== undefined) {
+          total.warningCount += current.warningCount;
+        }
+
         return total;
       }, {
         failures: [],
-        fixes: undefined
+        fixes: undefined,
+        errorCount: 0,
+        warningCount: 0,
       });
 
     if (!options.silent) {
@@ -119,21 +133,22 @@ export default Task.extend({
 
     // print formatter output directly for non human-readable formats
     if (['prose', 'verbose', 'stylish'].indexOf(options.format) == -1) {
-      return (result.failures.length == 0 || options.force)
-        ? Promise.resolve(0) : Promise.resolve(2);
+      options.silent = true;
     }
 
-    if (result.failures.length > 0) {
-      if (!options.silent) {
-        ui.writeLine(chalk.red('Lint errors found in the listed files.'));
-      }
-      return options.force ? Promise.resolve(0) : Promise.resolve(2);
+    if (result.warningCount > 0 && !options.silent) {
+      ui.writeLine(chalk.yellow('Lint warnings found in the listed files.'));
     }
 
-    if (!options.silent) {
+    if (result.errorCount > 0 && !options.silent) {
+      ui.writeLine(chalk.red('Lint errors found in the listed files.'));
+    }
+
+    if (result.warningCount === 0 && result.errorCount === 0 && !options.silent) {
       ui.writeLine(chalk.green('All files pass linting.'));
     }
-    return Promise.resolve(0);
+
+    return options.force || result.errorCount === 0 ? Promise.resolve(0) : Promise.resolve(2);
   }
 });