From a94f5e8cbb3e7f94fc9550a38d29b21c273050b5 Mon Sep 17 00:00:00 2001
From: Peter Bacon Darwin <pete@bacondarwin.com>
Date: Thu, 6 Jul 2017 12:17:57 +0100
Subject: [PATCH] build(aio): abort doc-gen if an example is missing

Closes #16936
---
 .../inline-tag-defs/example.spec.js                | 10 ++++++++--
 .../examples-package/services/getExampleRegion.js  | 14 +++++++-------
 .../services/getExampleRegion.spec.js              |  9 +++++++++
 3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/aio/tools/transforms/examples-package/inline-tag-defs/example.spec.js b/aio/tools/transforms/examples-package/inline-tag-defs/example.spec.js
index 5c32c38682..ec506b2c6c 100644
--- a/aio/tools/transforms/examples-package/inline-tag-defs/example.spec.js
+++ b/aio/tools/transforms/examples-package/inline-tag-defs/example.spec.js
@@ -31,8 +31,14 @@ describe('example inline-tag-def', function() {
       };
     });
 
-    it('should return a <code-example> tag', () => {
-      expect(handler({}, 'example', 'some/uri')).toEqual('<code-example>\n\n</code-example>');
+    it('should throw an error if there is no matching example', () => {
+      expect(function() {
+        handler({}, 'example', 'missing/uri');
+      }).toThrowError();
+
+      expect(function() {
+        handler({}, 'example', 'test/url missing-region');
+      }).toThrowError();
     });
 
     it('should contain the whole contents from the example file if no region is specified', () => {
diff --git a/aio/tools/transforms/examples-package/services/getExampleRegion.js b/aio/tools/transforms/examples-package/services/getExampleRegion.js
index bd26d084d8..47565942e0 100644
--- a/aio/tools/transforms/examples-package/services/getExampleRegion.js
+++ b/aio/tools/transforms/examples-package/services/getExampleRegion.js
@@ -1,4 +1,4 @@
-module.exports = function getExampleRegion(exampleMap, createDocMessage, log, collectExamples) {
+module.exports = function getExampleRegion(exampleMap, createDocMessage, collectExamples) {
   return function getExampleRegionImpl(doc, relativePath, regionName) {
     const EXAMPLES_FOLDERS = collectExamples.exampleFolders;
 
@@ -14,16 +14,16 @@ module.exports = function getExampleRegion(exampleMap, createDocMessage, log, co
 
     // If still no file then we error
     if (!exampleFile) {
-      log.error(createDocMessage('Missing example file... relativePath: "' + relativePath + '".', doc));
-      log.error('Example files can be found in: ' + EXAMPLES_FOLDERS.join(', '));
-      return '';
+      const message = createDocMessage('Missing example file... relativePath: "' + relativePath + '".', doc) + '\n' +
+                      'Example files can be found in: ' + EXAMPLES_FOLDERS.join(', ');
+      throw new Error(message);
     }
 
     var sourceCodeDoc = exampleFile.regions[regionName || ''];
     if (!sourceCodeDoc) {
-      log.error(createDocMessage('Missing example region... relativePath: "' + relativePath + '", region: "' + regionName + '".', doc));
-      log.error('Regions available are:', Object.keys[exampleFile.regions]);
-      return '';
+      const message = createDocMessage('Missing example region... relativePath: "' + relativePath + '", region: "' + regionName + '".', doc) + '\n' +
+                      'Regions available are:' + Object.keys[exampleFile.regions];
+      throw new Error(message);
     }
 
     return sourceCodeDoc.renderedContent;
diff --git a/aio/tools/transforms/examples-package/services/getExampleRegion.spec.js b/aio/tools/transforms/examples-package/services/getExampleRegion.spec.js
index cb189e70f9..b07ba44d7a 100644
--- a/aio/tools/transforms/examples-package/services/getExampleRegion.spec.js
+++ b/aio/tools/transforms/examples-package/services/getExampleRegion.spec.js
@@ -26,4 +26,13 @@ describe('getExampleRegion', () => {
   it('should contain the region contents from the example file if a region is specified', () => {
     expect(getExampleRegion({}, 'test/url', 'region-1')).toEqual('region 1 contents');
   });
+
+  it('should throw an error if an example doesn\'t exist', function() {
+    expect(function() {
+      getExampleRegion({}, 'missing/file', 'region-1');
+    }).toThrowError();
+    expect(function() {
+      getExampleRegion({}, 'test/url', 'missing-region');
+    }).toThrowError();
+  });
 });