Fix summary handling of unresolved imports, exports, and parts.

pkg/analyzer/test/src/summary/resynthesize_test.dart

Index: pkg/analyzer/test/src/summary/resynthesize_test.dart
diff --git a/pkg/analyzer/test/src/summary/resynthesize_test.dart b/pkg/analyzer/test/src/summary/resynthesize_test.dart
index 679741df4d764db3bace0143f962ec7f7f31167e..f7fe01c801808142c60c18a2e53747dd4927c6f0 100644
--- a/pkg/analyzer/test/src/summary/resynthesize_test.dart
+++ b/pkg/analyzer/test/src/summary/resynthesize_test.dart
@@ -49,6 +49,12 @@ abstract class AbstractResynthesizeTest extends AbstractSingleUnitTest {
    */
   Set<String> variablesWithNotConstInitializers = new Set<String>();
 
+  /**
+   * Tests may set this to `true` to indicate that a missing file at the time of

[Brian Wilkerson, 2016/08/11 23:49:35]

Seems odd to talk about setting a getter to `true`. :-)

I haven't thought about it very hard, but it also seems strange to make this
abstract when most of the overrides are "return false". Seems like it would be
easier to subclass this class if it just returned `false`, or was a field
initialized to `false`, but you probably had a reason for not doing that.

[Paul Berry, 2016/08/12 20:56:51]

Resolved in an offline discussion.  There was a slight complication due to a
strong mode error (a getter can't override a field, even if the getter is
abstract).  I've worked around that problem and made a request to see if we can
loosen the strong mode restriction.

+   * summary resynthesis shouldn't trigger an error.
+   */
+  bool get allowMissingFiles;
+
   bool get checkPropagatedTypes => true;
 
   void addLibrary(String uri) {
@@ -1184,7 +1190,7 @@ abstract class AbstractResynthesizeTest extends AbstractSingleUnitTest {
       });
     }
     return new TestSummaryResynthesizer(
-        null, context, unlinkedSummaries, linkedSummaries);
+        null, context, unlinkedSummaries, linkedSummaries, allowMissingFiles);
   }
 
   ElementImpl getActualElement(Element element, String desc) {
@@ -1331,13 +1337,6 @@ abstract class AbstractResynthesizeTest extends AbstractSingleUnitTest {
       return false;
     } else if (modifier == Modifier.SYNTHETIC) {
       return element.isSynthetic;
-    } else if (modifier == Modifier.URI_EXISTS) {
-      if (element is ExportElement) {
-        return element.uriExists;
-      } else if (element is ImportElement) {
-        return element.uriExists;
-      }
-      return false;
     }
     throw new UnimplementedError(
         'Modifier $modifier for ${element?.runtimeType}');
@@ -1347,6 +1346,9 @@ abstract class AbstractResynthesizeTest extends AbstractSingleUnitTest {
 @reflectiveTest
 class ResynthesizeElementTest extends ResynthesizeTest {
   @override
+  bool allowMissingFiles = false;
+
+  @override
   LibraryElementImpl checkLibrary(String text,
       {bool allowErrors: false, bool dumpSummaries: false}) {
     Source source = addTestSource(text);
@@ -1422,7 +1424,7 @@ class ResynthesizeElementTest extends ResynthesizeTest {
       });
     }
     return new TestSummaryResynthesizer(
-        null, context, unlinkedSummaries, linkedSummaries);
+        null, context, unlinkedSummaries, linkedSummaries, allowMissingFiles);
   }
 
   /**
@@ -1454,6 +1456,12 @@ class ResynthesizeElementTest extends ResynthesizeTest {
 
 @reflectiveTest
 abstract class ResynthesizeTest extends AbstractResynthesizeTest {
+  /**
+   * Tests may set this to `true` to indicate that a missing file at the time of
+   * summary resynthesis shouldn't trigger an error.
+   */
+  void set allowMissingFiles(bool value);
+
   LibraryElementImpl checkLibrary(String text,
       {bool allowErrors: false, bool dumpSummaries: false});
 
@@ -4476,6 +4484,21 @@ typedef F();''');
     checkLibrary('f() {} g() {}');
   }
 
+  test_unresolved_export() {
+    allowMissingFiles = true;
+    checkLibrary("export 'foo.dart';", allowErrors: true);
+  }
+
+  test_unresolved_import() {
+    allowMissingFiles = true;
+    checkLibrary("import 'foo.dart';", allowErrors: true);
+  }
+
+  test_unresolved_part() {
+    allowMissingFiles = true;
+    checkLibrary("part 'foo.dart';", allowErrors: true);
+  }
+
   test_unused_type_parameter() {
     checkLibrary('''
 class C<T> {
@@ -4588,6 +4611,7 @@ var x;''');
 class TestSummaryResynthesizer extends SummaryResynthesizer {
   final Map<String, UnlinkedUnit> unlinkedSummaries;
   final Map<String, LinkedLibrary> linkedSummaries;
+  final bool allowMissingFiles;
 
   /**
    * The set of uris for which unlinked summaries have been requested using
@@ -4602,7 +4626,7 @@ class TestSummaryResynthesizer extends SummaryResynthesizer {
   final Set<String> linkedSummariesRequested = new Set<String>();
 
   TestSummaryResynthesizer(SummaryResynthesizer parent, AnalysisContext context,
-      this.unlinkedSummaries, this.linkedSummaries)
+      this.unlinkedSummaries, this.linkedSummaries, this.allowMissingFiles)
       : super(parent, context, context.typeProvider, context.sourceFactory,
             context.analysisOptions.strongMode);
 
@@ -4610,7 +4634,7 @@ class TestSummaryResynthesizer extends SummaryResynthesizer {
   LinkedLibrary getLinkedSummary(String uri) {
     linkedSummariesRequested.add(uri);
     LinkedLibrary serializedLibrary = linkedSummaries[uri];
-    if (serializedLibrary == null) {
+    if (serializedLibrary == null && !allowMissingFiles) {
       fail('Unexpectedly tried to get linked summary for $uri');
     }
     return serializedLibrary;
@@ -4620,7 +4644,7 @@ class TestSummaryResynthesizer extends SummaryResynthesizer {
   UnlinkedUnit getUnlinkedSummary(String uri) {
     unlinkedSummariesRequested.add(uri);
     UnlinkedUnit serializedUnit = unlinkedSummaries[uri];
-    if (serializedUnit == null) {
+    if (serializedUnit == null && !allowMissingFiles) {
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;