Add Guice hints when the only difference between two types is when on…

…e is a wildcard type and the other is a non-wildcard type that is mentioned in the extends/super clause of the wildcard type (e.g. Optional<Foo> vs. Optional<? extends Foo>).

PiperOrigin-RevId: 696949702

core/src/com/google/inject/internal/MissingImplementationErrorHints.java

@@ -47,9 +47,9 @@ private MissingImplementationErrorHints() {}
   /**
    * Returns whether two types look similar (i.e. if you were to ignore their package). This helps
    * users who, for example, have injected the wrong Optional (java.util.Optional vs
-   * com.google.common.base.Optional). For generic types, the entire structure must match in
-   * addition to the simple names of the generic arguments (e.g. Optional<String> won't be
-   * similar to Optional<Integer>).
+   * com.google.common.base.Optional). For generic types, the entire structure must mostly match
+   * (wildcard types of extends and super can be ignored) in addition to the simple names of the
+   * generic arguments (e.g. Optional<String> won't be similar to Optional<Integer>).
    */
   static boolean areSimilarLookingTypes(Type a, Type b) {
     if (a instanceof Class && b instanceof Class) {
@@ -104,6 +104,24 @@ static boolean areSimilarLookingTypes(Type a, Type b) {
       }
       return true;
     }
+    // The next section handles when one type is a wildcard type and the other is not (e.g. to
+    // catch cases of `Foo` vs `? extends/super Foo`).
+    if (a instanceof WildcardType ^ b instanceof WildcardType) {
+      WildcardType wildcardType = a instanceof WildcardType ? (WildcardType) a : (WildcardType) b;
+      Type otherType = (wildcardType == a) ? b : a;
+      Type[] upperBounds = wildcardType.getUpperBounds();
+      Type[] lowerBounds = wildcardType.getLowerBounds();
+      if (upperBounds.length == 1 && lowerBounds.length == 0) {
+        // This is the '? extends Foo' case
+        return areSimilarLookingTypes(upperBounds[0], otherType);
+      }
+      if (lowerBounds.length == 1
+          && upperBounds.length == 1
+          && upperBounds[0].equals(Object.class)) {
+        // this is the '? super Foo' case
+        return areSimilarLookingTypes(lowerBounds[0], otherType);
+      }
+    }
     return false;
   }
 
@@ -116,25 +134,25 @@ static <T> ImmutableList<String> getSuggestions(Key<T> key, Injector injector) {
 
     // Keys which have similar strings as the desired key
     List<String> possibleMatches = new ArrayList<>();
-    ImmutableList<Binding<?>> sameTypes =
+    ImmutableList<Binding<?>> similarTypes =
         injector.getAllBindings().values().stream()
             .filter(b -> !(b instanceof UntargettedBinding)) // These aren't valid matches
             .filter(
                 b -> areSimilarLookingTypes(b.getKey().getTypeLiteral().getType(), type.getType()))
             .collect(toImmutableList());
-    if (!sameTypes.isEmpty()) {
+    if (!similarTypes.isEmpty()) {
       suggestions.add("\nDid you mean?");
-      int howMany = min(sameTypes.size(), MAX_MATCHING_TYPES_REPORTED);
+      int howMany = min(similarTypes.size(), MAX_MATCHING_TYPES_REPORTED);
       for (int i = 0; i < howMany; ++i) {
-        Key<?> bindingKey = sameTypes.get(i).getKey();
-        // TODO: Look into a better way to prioritize suggestions. For example, possbily
+        Key<?> bindingKey = similarTypes.get(i).getKey();
+        // TODO: Look into a better way to prioritize suggestions. For example, possibly
         // use levenshtein distance of the given annotation vs actual annotation.
         suggestions.add(
             Messages.format(
                 "\n    * %s",
                 formatSuggestion(bindingKey, injector.getExistingBinding(bindingKey))));
       }
-      int remaining = sameTypes.size() - MAX_MATCHING_TYPES_REPORTED;
+      int remaining = similarTypes.size() - MAX_MATCHING_TYPES_REPORTED;
       if (remaining > 0) {
         String plural = (remaining == 1) ? "" : "s";
         suggestions.add(
@@ -178,7 +196,7 @@ static <T> ImmutableList<String> getSuggestions(Key<T> key, Injector injector) {
 
     // If where are no possibilities to suggest, then handle the case of missing
     // annotations on simple types. This is usually a bad idea.
-    if (sameTypes.isEmpty()
+    if (similarTypes.isEmpty()
         && possibleMatches.isEmpty()
         && key.getAnnotationType() == null
         && COMMON_AMBIGUOUS_TYPES.contains(key.getTypeLiteral().getRawType())) {

core/test/com/google/inject/errors/BUILD

@@ -5,19 +5,33 @@ package(
     default_testonly = 1,
 )
 
+ERROR_MESSAGE_TEST_UTILS_SRCS = ["ErrorMessageTestUtils.java"]
+
+java_library(
+    name = "error_message_test_utils",
+    srcs = ERROR_MESSAGE_TEST_UTILS_SRCS,
+    deps = [
+        "//third_party/java/guava/io",
+        "//third_party/java/truth",
+    ],
+)
+
 java_library(
     name = "tests",
-    srcs = glob(["*.java"]),
+    srcs = glob(
+        ["*.java"],
+        exclude = ERROR_MESSAGE_TEST_UTILS_SRCS,
+    ),
     javacopts = ["-Xep:BetaApi:OFF"],
     resources = [
         ":test_error_files",
     ],
     deps = [
+        ":error_message_test_utils",
         "//core/src/com/google/inject",
         "//third_party/java/guava/annotations",
         "//third_party/java/guava/base",
         "//third_party/java/guava/collect",
-        "//third_party/java/guava/io",
         "//third_party/java/jakarta_inject",
         "//third_party/java/junit",
         "//third_party/java/truth",

core/test/com/google/inject/errors/testdata/missing_implementation_has_unnecessary_extends_clause.txt

@@ -0,0 +1,26 @@
+Unable to create injector, see the following errors:
+
+1) [Guice/MissingImplementation]: No implementation for MissingImplementationErrorKtTest$Producer<? extends MissingImplementationErrorKtTest$Foo> was bound.
+
+Did you mean?
+    * MissingImplementationErrorKtTest$Producer<MissingImplementationErrorKtTest$Foo> bound at MissingImplementationErrorKtTest$InjectionHasUnnecessaryExtendsClauseModule.provideProducerOfFoo(MissingImplementationErrorKtTest.kt:53)
+
+Requested by:
+1  : MissingImplementationErrorKtTest$InjectionHasUnnecessaryExtendsClauseModule.injectProducerOfFoo(MissingImplementationErrorKtTest.kt:58)
+      \_ for 1st parameter unused
+     at MissingImplementationErrorKtTest$InjectionHasUnnecessaryExtendsClauseModule.injectProducerOfFoo(MissingImplementationErrorKtTest.kt:58)
+
+Learn more:
+  https://github.com/google/guice/wiki/MISSING_IMPLEMENTATION
+
+1 error
+
+======================
+Full classname legend:
+======================
+MissingImplementationErrorKtTest$Foo:                                        "com.google.inject.errors.MissingImplementationErrorKtTest$Foo"
+MissingImplementationErrorKtTest$InjectionHasUnnecessaryExtendsClauseModule: "com.google.inject.errors.MissingImplementationErrorKtTest$InjectionHasUnnecessaryExtendsClauseModule"
+MissingImplementationErrorKtTest$Producer:                                   "com.google.inject.errors.MissingImplementationErrorKtTest$Producer"
+========================
+End of classname legend:
+========================

core/test/com/google/inject/errors/testdata/missing_implementation_has_unnecessary_super_clause.txt

@@ -0,0 +1,26 @@
+Unable to create injector, see the following errors:
+
+1) [Guice/MissingImplementation]: No implementation for MissingImplementationErrorKtTest$Consumer<? super MissingImplementationErrorKtTest$Foo> was bound.
+
+Did you mean?
+    * MissingImplementationErrorKtTest$Consumer<MissingImplementationErrorKtTest$Foo> bound at MissingImplementationErrorKtTest$InjectionHasUnnecessarySuperClauseModule.provideConsumerOfFoo(MissingImplementationErrorKtTest.kt:98)
+
+Requested by:
+1  : MissingImplementationErrorKtTest$InjectionHasUnnecessarySuperClauseModule.injectConsumerOfFoo(MissingImplementationErrorKtTest.kt:103)
+      \_ for 1st parameter unused
+     at MissingImplementationErrorKtTest$InjectionHasUnnecessarySuperClauseModule.injectConsumerOfFoo(MissingImplementationErrorKtTest.kt:103)
+
+Learn more:
+  https://github.com/google/guice/wiki/MISSING_IMPLEMENTATION
+
+1 error
+
+======================
+Full classname legend:
+======================
+MissingImplementationErrorKtTest$Consumer:                                 "com.google.inject.errors.MissingImplementationErrorKtTest$Consumer"
+MissingImplementationErrorKtTest$Foo:                                      "com.google.inject.errors.MissingImplementationErrorKtTest$Foo"
+MissingImplementationErrorKtTest$InjectionHasUnnecessarySuperClauseModule: "com.google.inject.errors.MissingImplementationErrorKtTest$InjectionHasUnnecessarySuperClauseModule"
+========================
+End of classname legend:
+========================

core/test/com/google/inject/errors/testdata/missing_implementation_missing_extends_clause.txt

@@ -0,0 +1,26 @@
+Unable to create injector, see the following errors:
+
+1) [Guice/MissingImplementation]: No implementation for MissingImplementationErrorKtTest$Producer<MissingImplementationErrorKtTest$Foo> was bound.
+
+Did you mean?
+    * MissingImplementationErrorKtTest$Producer<? extends MissingImplementationErrorKtTest$Foo> bound at MissingImplementationErrorKtTest$InjectionMissingExtendsClauseModule.configure(MissingImplementationErrorKtTest.kt:118)
+
+Requested by:
+1  : MissingImplementationErrorKtTest$InjectionMissingExtendsClauseModule.injectProducerOfFoo(MissingImplementationErrorKtTest.kt:36)
+      \_ for 1st parameter unused
+     at MissingImplementationErrorKtTest$InjectionMissingExtendsClauseModule.injectProducerOfFoo(MissingImplementationErrorKtTest.kt:36)
+
+Learn more:
+  https://github.com/google/guice/wiki/MISSING_IMPLEMENTATION
+
+1 error
+
+======================
+Full classname legend:
+======================
+MissingImplementationErrorKtTest$Foo:                                 "com.google.inject.errors.MissingImplementationErrorKtTest$Foo"
+MissingImplementationErrorKtTest$InjectionMissingExtendsClauseModule: "com.google.inject.errors.MissingImplementationErrorKtTest$InjectionMissingExtendsClauseModule"
+MissingImplementationErrorKtTest$Producer:                            "com.google.inject.errors.MissingImplementationErrorKtTest$Producer"
+========================
+End of classname legend:
+========================

core/test/com/google/inject/errors/testdata/missing_implementation_missing_super_clause.txt

@@ -0,0 +1,26 @@
+Unable to create injector, see the following errors:
+
+1) [Guice/MissingImplementation]: No implementation for MissingImplementationErrorKtTest$Consumer<MissingImplementationErrorKtTest$Foo> was bound.
+
+Did you mean?
+    * MissingImplementationErrorKtTest$Consumer<? super MissingImplementationErrorKtTest$Foo> bound at MissingImplementationErrorKtTest$InjectionMissingSuperClauseModule.configure(MissingImplementationErrorKtTest.kt:118)
+
+Requested by:
+1  : MissingImplementationErrorKtTest$InjectionMissingSuperClauseModule.injectConsumerOfFoo(MissingImplementationErrorKtTest.kt:81)
+      \_ for 1st parameter unused
+     at MissingImplementationErrorKtTest$InjectionMissingSuperClauseModule.injectConsumerOfFoo(MissingImplementationErrorKtTest.kt:81)
+
+Learn more:
+  https://github.com/google/guice/wiki/MISSING_IMPLEMENTATION
+
+1 error
+
+======================
+Full classname legend:
+======================
+MissingImplementationErrorKtTest$Consumer:                          "com.google.inject.errors.MissingImplementationErrorKtTest$Consumer"
+MissingImplementationErrorKtTest$Foo:                               "com.google.inject.errors.MissingImplementationErrorKtTest$Foo"
+MissingImplementationErrorKtTest$InjectionMissingSuperClauseModule: "com.google.inject.errors.MissingImplementationErrorKtTest$InjectionMissingSuperClauseModule"
+========================
+End of classname legend:
+========================

core/test/com/google/inject/internal/SimilarLookingTypesTest.java

@@ -83,6 +83,42 @@ public void similarWildcardTypes() {
         .isTrue();
   }
 
+  @Test
+  public void similarExtendsCase() {
+    assertThat(
+            areSimilarLookingTypes(
+                new TypeLiteral<Optional<Foo>>() {}.getType(),
+                new TypeLiteral<Optional<? extends Foo>>() {}.getType()))
+        .isTrue();
+  }
+
+  @Test
+  public void differentExtendsCase() {
+    assertThat(
+            areSimilarLookingTypes(
+                new TypeLiteral<Optional<String>>() {}.getType(),
+                new TypeLiteral<Optional<? extends Foo>>() {}.getType()))
+        .isFalse();
+  }
+
+  @Test
+  public void similarSuperCase() {
+    assertThat(
+            areSimilarLookingTypes(
+                new TypeLiteral<Optional<Foo>>() {}.getType(),
+                new TypeLiteral<Optional<? super Foo>>() {}.getType()))
+        .isTrue();
+  }
+
+  @Test
+  public void differentSuperCase() {
+    assertThat(
+            areSimilarLookingTypes(
+                new TypeLiteral<Optional<String>>() {}.getType(),
+                new TypeLiteral<Optional<? super Foo>>() {}.getType()))
+        .isFalse();
+  }
+
   @Test
   public void differentWildcardType_extends() {
     assertThat(