Automatically remove empty entries from the cache.

pkg/analyzer/test/src/context/cache_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.src.task.driver_test;
 
 import 'package:analyzer/src/context/cache.dart';
 import 'package:analyzer/src/generated/engine.dart'
     show
         AnalysisContext,
@@ skipping 114 matching lines @@
     entry.setErrorState(exception, <ResultDescriptor>[result]);
     entry.fixExceptionState();
     expect(entry.getState(result), CacheState.ERROR);
     expect(entry.exception, exception);
   }
 
   test_fixExceptionState_noError_exception() {
     AnalysisTarget target = new TestSource();
     ResultDescriptor result = new ResultDescriptor('test', null);
     CacheEntry entry = new CacheEntry(target);
+    cache.put(entry);
     // set one result to ERROR
     CaughtException exception = new CaughtException(null, null);
     entry.setErrorState(exception, <ResultDescriptor>[result]);
     // set the same result to VALID
     entry.setValue(result, 1, TargetedResult.EMPTY_LIST);
     // fix the exception state
     entry.fixExceptionState();
     expect(entry.exception, isNull);
   }
 
@@ skipping 205 matching lines @@
     // set IN_PROCESS
     entry.setState(result, CacheState.IN_PROCESS);
     expect(entry.getState(result), CacheState.IN_PROCESS);
     expect(entry.getValue(result), 10);
   }
 
   test_setState_invalid() {
     AnalysisTarget target = new TestSource();
     ResultDescriptor result = new ResultDescriptor('test', 1);
     CacheEntry entry = new CacheEntry(target);
+    cache.put(entry);
     // set VALID
     entry.setValue(result, 10, TargetedResult.EMPTY_LIST);
     expect(entry.getState(result), CacheState.VALID);
     expect(entry.getValue(result), 10);
     // set INVALID
     entry.setState(result, CacheState.INVALID);
     expect(entry.getState(result), CacheState.INVALID);
     expect(entry.getValue(result), 1);
   }
 
@@ skipping 21 matching lines @@
     // invalidate result1, invalidates result2 and result3, result4 is intact
     entry.setState(result1, CacheState.INVALID);
     expect(entry.getState(result1), CacheState.INVALID);
     expect(entry.getState(result2), CacheState.INVALID);
     expect(entry.getState(result3), CacheState.INVALID);
     expect(entry.getState(result4), CacheState.VALID);
     expect(entry.getValue(result1), -1);
     expect(entry.getValue(result2), -2);
     expect(entry.getValue(result3), -3);
     expect(entry.getValue(result4), 444);
+    // result4 is still valid, so the entry is still in the cache
+    expect(cache.get(target), entry);
+  }
+
+  test_setState_invalid_removeEmptyEntry() {
+    AnalysisTarget target1 = new TestSource('/a.dart');
+    AnalysisTarget target2 = new TestSource('/b.dart');
+    CacheEntry entry1 = new CacheEntry(target1);
+    CacheEntry entry2 = new CacheEntry(target2);
+    cache.put(entry1);
+    cache.put(entry2);
+    ResultDescriptor result1 = new ResultDescriptor('result1', -1);
+    ResultDescriptor result2 = new ResultDescriptor('result2', -2);
+    ResultDescriptor result3 = new ResultDescriptor('result3', -3);
+    // set results, all of them are VALID
+    entry1.setValue(result1, 111, TargetedResult.EMPTY_LIST);
+    entry2.setValue(result2, 222, [new TargetedResult(target1, result1)]);
+    entry2.setValue(result3, 333, [new TargetedResult(target2, result2)]);
+    expect(entry1.getState(result1), CacheState.VALID);
+    expect(entry2.getState(result2), CacheState.VALID);
+    expect(entry2.getState(result3), CacheState.VALID);
+    expect(entry1.getValue(result1), 111);
+    expect(entry2.getValue(result2), 222);
+    expect(entry2.getValue(result3), 333);
+    // invalidate result1, remove entry1 & entry2
+    entry1.setState(result1, CacheState.INVALID);
+    expect(cache.get(target1), isNull);
+    expect(cache.get(target2), isNull);
   }
 
   test_setState_valid() {
     AnalysisTarget target = new TestSource();
     ResultDescriptor result = new ResultDescriptor('test', null);
     CacheEntry entry = new CacheEntry(target);
     expect(() => entry.setState(result, CacheState.VALID), throwsArgumentError);
   }
 
   test_setValue() {
@@ skipping 90 matching lines @@
     // set result1, invalidates result2 and result3
     entry1.setValue(result1, 1111, TargetedResult.EMPTY_LIST);
     expect(entry1.getState(result1), CacheState.VALID);
     expect(entry1.getState(result2), CacheState.INVALID);
     expect(entry2.getState(result3), CacheState.INVALID);
     expect(entry1.getValue(result1), 1111);
     expect(entry1.getValue(result2), -2);
     expect(entry2.getValue(result3), -3);
   }
 
+  test_setValue_keepEntry() {
+    AnalysisTarget target1 = new TestSource('/a.dart');
+    AnalysisTarget target2 = new TestSource('/b.dart');
+    CacheEntry entry1 = new CacheEntry(target1);
+    CacheEntry entry2 = new CacheEntry(target2);
+    cache.put(entry1);
+    cache.put(entry2);
+    ResultDescriptor result1 = new ResultDescriptor('result1', -1);
+    ResultDescriptor result2 = new ResultDescriptor('result2', -2);
+    // set results, all of them are VALID
+    entry1.setValue(result1, 111, TargetedResult.EMPTY_LIST);
+    entry2.setValue(result2, 222, [new TargetedResult(target1, result1)]);
+    expect(entry1.getState(result1), CacheState.VALID);
+    expect(entry2.getState(result2), CacheState.VALID);
+    expect(entry1.getValue(result1), 111);
+    expect(entry2.getValue(result2), 222);
+    // set result2, entry2 is still in the cache
+    entry2.setValue(result2, 2222, []);
+    expect(cache.get(target1), entry1);
+    expect(cache.get(target2), entry2);
+  }
+
   test_toString_empty() {
     AnalysisTarget target = new TestSource();
     CacheEntry entry = new CacheEntry(target);
     expect(entry.toString(), isNotNull);
   }
 
   test_toString_nonEmpty() {
     AnalysisTarget target = new TestSource();
     ResultDescriptor result = new ResultDescriptor('test', null);
     CacheEntry entry = new CacheEntry(target);
@@ skipping 248 matching lines @@
     UniversalCachePartition partition = new UniversalCachePartition(null);
     TestSource source = new TestSource();
     expect(partition.isResponsibleFor(source), isTrue);
   }
 }
 
 class _InternalAnalysisContextMock extends TypedMock
     implements InternalAnalysisContext {
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }