Fix templates in one liners (#2383)

* Add a basic test

* Fix test so it actually reproduces the problem

* Fix weird wheretype

Author: jcollins-g

lib/src/model/package_graph.dart

@@ -125,10 +125,20 @@ class PackageGraph {
 
     for (var m in allModelElements) {
       // Skip if there is a canonicalModelElement somewhere else we can run this
-      // for.  Not the same as allCanonicalModelElements since we need to run
+      // for and we won't need a one line document that is precached.
+      // Not the same as allCanonicalModelElements since we need to run
       // for any ModelElement that might not have a canonical ModelElement,
       // too.
-      if (m.canonicalModelElement != null && !m.isCanonical) continue;
+      if (m.canonicalModelElement !=
+                  null // A canonical element exists somewhere
+              &&
+              !m.isCanonical // This element is not canonical
+              &&
+              !m.enclosingElement
+                  .isCanonical // The enclosingElement won't need a oneLineDoc from this
+          ) {
+        continue;
+      }
       yield* precacheOneElement(m);
     }
   }

test/end2end/model_test.dart

@@ -610,7 +610,7 @@ void main() {
   });
 
   group('Macros', () {
-    Class dog;
+    Class dog, ClassTemplateOneLiner;
     Enum MacrosFromAccessors;
     Method withMacro, withMacro2, withPrivateMacro, withUndefinedMacro;
     EnumField macroReferencedHere;
@@ -628,6 +628,16 @@ void main() {
           fakeLibrary.enums.firstWhere((e) => e.name == 'MacrosFromAccessors');
       macroReferencedHere = MacrosFromAccessors.publicConstantFields
           .firstWhere((e) => e.name == 'macroReferencedHere');
+      ClassTemplateOneLiner = exLibrary.allClasses
+          .firstWhere((c) => c.name == 'ClassTemplateOneLiner');
+    });
+
+    test('via reexport does not leave behind template crumbs', () {
+      expect(ClassTemplateOneLiner.isCanonical, isFalse);
+      expect(
+          ClassTemplateOneLiner.oneLineDoc,
+          equals(
+              'I had better not have a template directive in my one liner.'));
     });
 
     test('renders a macro defined within a enum', () {
@@ -1503,7 +1513,7 @@ void main() {
     });
 
     test('correctly finds all the classes', () {
-      expect(classes, hasLength(36));
+      expect(classes, hasLength(37));
     });
 
     test('abstract', () {

testing/test_package/lib/example.dart

@@ -11,7 +11,7 @@ import 'package:test_package_imported/main.dart';
 export 'dart:core' show deprecated, Deprecated;
 import 'package:meta/meta.dart' show protected, factory;
 
-export 'fake.dart' show Cool;
+export 'fake.dart' show Cool, ClassTemplateOneLiner;
 export 'src/mylib.dart' show Helper;
 
 const String COLOR = 'red';

testing/test_package/lib/fake.dart

@@ -73,6 +73,8 @@ export 'src/tool.dart';
 // ignore: uri_does_not_exist
 export 'package:test_package/fake.dart';
 
+export 'src/reexport_this.dart';
+
 /// Does not render with emoji 3ffe:2a00:100:7031::1
 const int hasMarkdownInDoc = 1;
 

testing/test_package/lib/src/reexport_this.dart

@@ -0,0 +1,12 @@
+
+library reexport_this;
+
+/// {@template example:templateMemberTest}
+/// I had better not have a template directive in my one liner.
+///
+/// Even if it has links to [Dog] or other classes.
+///
+/// And if I do, a test should fail.
+/// {@endtemplate}
+class ClassTemplateOneLiner {
+}