From af99cf2a41f13f267c7365c2ea296f587c5d51d6 Mon Sep 17 00:00:00 2001
From: Pete Bacon Darwin <pete@bacondarwin.com>
Date: Tue, 16 May 2017 18:21:31 +0100
Subject: [PATCH] build(aio): compute `{@link ...} titles more effectively
 (#16813)

If a usage of `{@link ...}` does not provide a title then
compute it based on the `title` and/or `name` properties
or set the link to invalid.

Closes #16811
---
 .../links-package/services/getLinkInfo.js     |  6 ++-
 .../services/getLinkInfo.spec.js              | 51 +++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 aio/tools/transforms/links-package/services/getLinkInfo.spec.js

diff --git a/aio/tools/transforms/links-package/services/getLinkInfo.js b/aio/tools/transforms/links-package/services/getLinkInfo.js
index e2cbe2c4d8..c09e1fddf6 100644
--- a/aio/tools/transforms/links-package/services/getLinkInfo.js
+++ b/aio/tools/transforms/links-package/services/getLinkInfo.js
@@ -44,7 +44,7 @@ module.exports = function getLinkInfo(getDocFromAlias, encodeCodeBlock, log) {
 
     } else if (docs.length >= 1) {
       linkInfo.url = docs[0].path;
-      linkInfo.title = title || encodeCodeBlock(docs[0].name, true);
+      linkInfo.title = title || docs[0].title || docs[0].name && encodeCodeBlock(docs[0].name, true);
       linkInfo.type = 'doc';
 
       if (getLinkInfoImpl.relativeLinks && currentDoc && currentDoc.path) {
@@ -72,6 +72,10 @@ module.exports = function getLinkInfo(getDocFromAlias, encodeCodeBlock, log) {
           title || ((url.indexOf('#') === 0) ? url.substring(1) : path.basename(url, '.html'));
     }
 
+    if (linkInfo.title === undefined) {
+      linkInfo.valid = false;
+    }
+
     return linkInfo;
   }
 
diff --git a/aio/tools/transforms/links-package/services/getLinkInfo.spec.js b/aio/tools/transforms/links-package/services/getLinkInfo.spec.js
new file mode 100644
index 0000000000..58951c4040
--- /dev/null
+++ b/aio/tools/transforms/links-package/services/getLinkInfo.spec.js
@@ -0,0 +1,51 @@
+const testPackage = require('../../helpers/test-package');
+const Dgeni = require('dgeni');
+
+let getLinkInfo, aliasMap;
+
+describe('getLinkInfo', () => {
+  beforeEach(function() {
+    var dgeni = new Dgeni([testPackage('links-package', true)]);
+    var injector = dgeni.configureInjector();
+    aliasMap = injector.get('aliasMap');
+    getLinkInfo = injector.get('getLinkInfo');
+  });
+
+  it('should use the title if specified', () => {
+    aliasMap.addDoc({ docType: 'guide', title: 'Browser Support', name: 'browser-support', id: 'guide/browser-support', aliases: ['guide/browser-support', 'browser-support'], path: 'guide/browser-support' });
+    const currentDoc = { };
+    const linkInfo = getLinkInfo('browser-support', '"Browser Support Guide"', currentDoc);
+    expect(linkInfo.title).toBe('"Browser Support Guide"');
+  });
+
+  it('should set the link to invalid if the title is `undefined`', () => {
+    aliasMap.addDoc({ docType: 'guide', id: 'guide/browser-support', aliases: ['guide/browser-support', 'browser-support'], path: 'guide/browser-support' });
+    const currentDoc = { };
+    const linkInfo = getLinkInfo('browser-support', undefined, currentDoc);
+    expect(linkInfo.valid).toBe(false);
+  });
+
+  it('should use the target document title if available and no title is specified', () => {
+    aliasMap.addDoc({ docType: 'guide', title: 'Browser Support', id: 'guide/browser-support', aliases: ['guide/browser-support', 'browser-support'], path: 'guide/browser-support' });
+    const currentDoc = { };
+    const linkInfo = getLinkInfo('browser-support', undefined, currentDoc);
+    expect(linkInfo.valid).toBe(true);
+    expect(linkInfo.title).toEqual('Browser Support');
+  });
+
+  it('should prefer the target doc title over name if available and no title is specified', () => {
+    aliasMap.addDoc({ docType: 'guide', title: 'Browser Support', name: 'browser-support', id: 'guide/browser-support', aliases: ['guide/browser-support', 'browser-support'], path: 'guide/browser-support' });
+    const currentDoc = { };
+    const linkInfo = getLinkInfo('browser-support', undefined, currentDoc);
+    expect(linkInfo.valid).toBe(true);
+    expect(linkInfo.title).toEqual('Browser Support');
+  });
+
+  it('should use the target document name as a code block if available and no title is specified', () => {
+    aliasMap.addDoc({ docType: 'api', name: 'CurrencyPipe', id: 'common/CurrencyPipe', aliases: ['common/CurrencyPipe', 'CurrencyPipe'], path: 'api/common/CurrencyPipe' });
+    const currentDoc = { };
+    const linkInfo = getLinkInfo('CurrencyPipe', undefined, currentDoc);
+    expect(linkInfo.valid).toBe(true);
+    expect(linkInfo.title).toEqual('<code>CurrencyPipe</code>');
+  });
+});
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