Move the e2e source-link test to a unit test (#3254)

Author: srawlins

test/end2end/dartdoc_test.dart

@@ -148,21 +148,6 @@ void main() {
             hasLength(kTestPackagePublicLibraries + 2));
         expect(packageGraph.localPackages.length, equals(1));
       });
-
-      test('source code links are visible', () async {
-        // Picked this object as this library explicitly should never contain
-        // a library directive, so we can predict what line number it will be.
-        var anonymousOutput = _resourceProvider.getFile(_pathContext.join(
-            tempDir.path,
-            'anonymous_library',
-            'anonymous_library-library.html'));
-        expect(anonymousOutput.exists, isTrue);
-        expect(
-            anonymousOutput.readAsStringSync(),
-            contains(r'<a title="View source code" class="source-link" '
-                'href="https://github.com/dart-lang/dartdoc/blob/master/testing/test_package/lib/anonymous_library.dart#L1">'
-                '<span class="material-symbols-outlined">description</span></a>'));
-      });
     });
 
     test('generate docs for ${p.basename(_testPackageBadDir.path)} fails',

test/templates/extension_test.dart

@@ -97,6 +97,12 @@ extension E<T> on C<T> {
 }
 '''),
         ],
+        dartdocOptions: '''
+dartdoc:
+  linkToSource:
+    root: '.'
+    uriTemplate: 'https://github.com/dart-lang/TEST_PKG/%f%#L%l%'
+''',
         resourceProvider: resourceProvider,
       );
       await writeDartdocResources(resourceProvider);
@@ -200,14 +206,15 @@ extension E<T> on C<T> {
 
     test('enum sidebar contains static properties', () async {
       expect(
-          eLines,
-          containsAllInOrder([
-            matches('<div id="dartdoc-sidebar-right"'),
-            matches(
-                '<a href="../lib/E.html#static-properties">Static properties</a>'),
-            matches('<a href="../lib/E/gs1.html">gs1</a>'),
-            matches('<a href="../lib/E/sf1.html">sf1</a>'),
-          ]));
+        eLines,
+        containsAllInOrder([
+          matches('<div id="dartdoc-sidebar-right"'),
+          matches(
+              '<a href="../lib/E.html#static-properties">Static properties</a>'),
+          matches('<a href="../lib/E/gs1.html">gs1</a>'),
+          matches('<a href="../lib/E/sf1.html">sf1</a>'),
+        ]),
+      );
     });
 
     test('enum sidebar contains static methods', () async {
@@ -220,5 +227,16 @@ extension E<T> on C<T> {
             matches('<a href="../lib/E/s1.html">s1</a>'),
           ]));
     });
+
+    test('extension page contains source link', () async {
+      expect(
+        eLines,
+        containsAllInOrder([
+          matches('<a title="View source code" class="source-link" '
+              'href="https://github.com/dart-lang/TEST_PKG/lib/lib.dart#L5">'
+              '<span class="material-symbols-outlined">description</span></a>'),
+        ]),
+      );
+    });
   });
 }