1 files changed, 108 insertions, 0 deletions
diff --git a/src/test/java/com/google/devtools/build/lib/vfs/DigestHashFunctionGlobalsTest.java b/src/test/java/com/google/devtools/build/lib/vfs/DigestHashFunctionGlobalsTest.java
new file mode 100644
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+++ b/src/test/java/com/google/devtools/build/lib/vfs/DigestHashFunctionGlobalsTest.java
@@ -0,0 +1,108 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.lib.vfs;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;
+
+import com.google.common.hash.Hashing;
+import com.google.devtools.build.lib.vfs.DigestHashFunction.DigestFunctionConverter;
+import java.lang.reflect.Field;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/**
+ * Tests for DigestHashFunction, notably that the static instances can be compared with reference
+ * equality.
+ */
+@RunWith(JUnit4.class)
+public class DigestHashFunctionGlobalsTest {
+  private final DigestFunctionConverter converter = new DigestFunctionConverter();
+
+  @Before
+  public void resetStaticDefault() throws IllegalAccessException, NoSuchFieldException {
+    // The default is effectively a Singleton, and it does not allow itself to be set multiple
+    // times. In order to test this reasonably, though, we reset the sentinel boolean to false and
+    // the value to null, which are the values before setDefault is called.
+    Field defaultHasBeenSet = DigestHashFunction.class.getDeclaredField("defaultHasBeenSet");
+    defaultHasBeenSet.setAccessible(true);
+    defaultHasBeenSet.set(null, false);
+
+    Field defaultValue = DigestHashFunction.class.getDeclaredField("defaultHash");
+    defaultValue.setAccessible(true);
+    defaultValue.set(null, null);
+  }
+
+  @Test
+  public void convertReturnsTheSameValueAsTheConstant() throws Exception {
+    assertThat(converter.convert("sha-256")).isSameAs(DigestHashFunction.SHA256);
+    assertThat(converter.convert("SHA-256")).isSameAs(DigestHashFunction.SHA256);
+    assertThat(converter.convert("SHA256")).isSameAs(DigestHashFunction.SHA256);
+    assertThat(converter.convert("sha256")).isSameAs(DigestHashFunction.SHA256);
+
+    assertThat(converter.convert("SHA-1")).isSameAs(DigestHashFunction.SHA1);
+    assertThat(converter.convert("sha-1")).isSameAs(DigestHashFunction.SHA1);
+    assertThat(converter.convert("SHA1")).isSameAs(DigestHashFunction.SHA1);
+    assertThat(converter.convert("sha1")).isSameAs(DigestHashFunction.SHA1);
+
+    assertThat(converter.convert("MD5")).isSameAs(DigestHashFunction.MD5);
+    assertThat(converter.convert("md5")).isSameAs(DigestHashFunction.MD5);
+  }
+
+  @Test
+  public void lateRegistrationGetsPickedUpByConverter() throws Exception {
+    DigestHashFunction.register(Hashing.goodFastHash(32), "SHA-512");
+
+    assertThat(converter.convert("SHA-512")).isSameAs(converter.convert("sha-512"));
+  }
+
+  @Test
+  public void lateRegistrationWithAlternativeNamesGetsPickedUpByConverter() throws Exception {
+    DigestHashFunction.register(Hashing.goodFastHash(64), "SHA-384", "SHA384", "SHA_384");
+
+    assertThat(converter.convert("SHA-384")).isSameAs(converter.convert("SHA-384"));
+    assertThat(converter.convert("Sha-384")).isSameAs(converter.convert("SHA-384"));
+    assertThat(converter.convert("sha-384")).isSameAs(converter.convert("SHA-384"));
+
+    assertThat(converter.convert("SHA384")).isSameAs(converter.convert("SHA-384"));
+    assertThat(converter.convert("Sha384")).isSameAs(converter.convert("SHA-384"));
+    assertThat(converter.convert("sha384")).isSameAs(converter.convert("SHA-384"));
+
+    assertThat(converter.convert("SHA_384")).isSameAs(converter.convert("SHA-384"));
+    assertThat(converter.convert("Sha_384")).isSameAs(converter.convert("SHA-384"));
+    assertThat(converter.convert("sha_384")).isSameAs(converter.convert("SHA-384"));
+  }
+
+  @Test
+  public void unsetDefaultThrows() {
+    assertThrows(
+        DigestHashFunction.DefaultNotSetException.class, () -> DigestHashFunction.getDefault());
+  }
+
+  @Test
+  public void setDefaultDoesNotThrow() throws Exception {
+    DigestHashFunction.setDefault(DigestHashFunction.SHA1);
+    DigestHashFunction.getDefault();
+  }
+
+  @Test
+  public void cannotSetDefaultMultipleTimes() throws Exception {
+    DigestHashFunction.setDefault(DigestHashFunction.MD5);
+    assertThrows(
+        DigestHashFunction.DefaultAlreadySetException.class,
+        () -> DigestHashFunction.setDefault(DigestHashFunction.SHA1));
+  }
+}