PathFragment comparisons are now platform-aware

PathFragment's `equals`, `hashCode`, `compareTo`,
`startsWith`, `endsWith`, and `relativeTo` are now
aware of case-insensitivity when running on
Windows.

This approach is better than
https://bazel-review.googlesource.com/c/9124/
because it preserves path casing, which is
important when computing action output paths.

This change contains two additional bugfixes:
- `compareTo` now takes `driveLetter` into account
- the `InMemoryFileSystem` in `PathWindowsTest` is
not case-insensitive

Fixes https://github.com/bazelbuild/bazel/issues/2613

--
Change-Id: I1a4250a373fff03fa02a6d8360457450b47a42a8
Reviewed-on: https://cr.bazel.build/9126
PiperOrigin-RevId: 149106930
MOS_MIGRATED_REVID=149106930

1 files changed, 55 insertions, 0 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/windows/PathWindowsTest.java b/src/test/java/com/google/devtools/build/lib/windows/PathWindowsTest.java
index 388c3fd754..04015dd28f 100644
--- a/src/test/java/com/google/devtools/build/lib/windows/PathWindowsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/windows/PathWindowsTest.java
@@ -24,6 +24,7 @@ import com.google.devtools.build.lib.vfs.FileSystem;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.Path.PathFactory;
 import com.google.devtools.build.lib.vfs.PathFragment;
+import com.google.devtools.build.lib.vfs.RootedPath;
 import com.google.devtools.build.lib.vfs.inmemoryfs.InMemoryFileSystem;
 import com.google.devtools.build.lib.windows.WindowsFileSystem.WindowsPath;
 import java.util.ArrayList;
@@ -65,6 +66,11 @@ public class PathWindowsTest {
           protected PathFactory getPathFactory() {
             return WindowsFileSystem.getPathFactoryForTesting(shortPathResolver);
           }
+
+          @Override
+          public boolean isFilePathCaseSensitive() {
+            return false;
+          }
         };
     root = (WindowsPath) filesystem.getRootDirectory().getRelative("C:/");
     root.createDirectory();
@@ -280,4 +286,53 @@ public class PathWindowsTest {
             "D:/program files/microsoft something/foo/~bar_hello",
             "D:/program files/microsoft something/foo/will.exist");
   }
+
+  @Test
+  public void testCaseInsensitivePathFragment() {
+    // equals
+    assertThat(new PathFragment("c:/FOO/BAR")).isEqualTo(new PathFragment("c:\\foo\\bar"));
+    assertThat(new PathFragment("c:/FOO/BAR")).isNotEqualTo(new PathFragment("d:\\foo\\bar"));
+    assertThat(new PathFragment("c:/FOO/BAR")).isNotEqualTo(new PathFragment("/foo/bar"));
+    // equals for the string representation
+    assertThat(new PathFragment("c:/FOO/BAR").toString())
+        .isNotEqualTo(new PathFragment("c:/foo/bar").toString());
+    // hashCode
+    assertThat(new PathFragment("c:/FOO/BAR").hashCode())
+        .isEqualTo(new PathFragment("c:\\foo\\bar").hashCode());
+    assertThat(new PathFragment("c:/FOO/BAR").hashCode())
+        .isNotEqualTo(new PathFragment("d:\\foo\\bar").hashCode());
+    assertThat(new PathFragment("c:/FOO/BAR").hashCode())
+        .isNotEqualTo(new PathFragment("/foo/bar").hashCode());
+    // compareTo
+    assertThat(new PathFragment("c:/FOO/BAR").compareTo(new PathFragment("c:\\foo\\bar")))
+        .isEqualTo(0);
+    assertThat(new PathFragment("c:/FOO/BAR").compareTo(new PathFragment("d:\\foo\\bar")))
+        .isLessThan(0);
+    assertThat(new PathFragment("c:/FOO/BAR").compareTo(new PathFragment("/foo/bar")))
+        .isGreaterThan(0);
+    // startsWith
+    assertThat(new PathFragment("c:/FOO/BAR").startsWith(new PathFragment("c:\\foo"))).isTrue();
+    assertThat(new PathFragment("c:/FOO/BAR").startsWith(new PathFragment("d:\\foo"))).isFalse();
+    // endsWith
+    assertThat(new PathFragment("c:/FOO/BAR/BAZ").endsWith(new PathFragment("bar\\baz"))).isTrue();
+    assertThat(new PathFragment("c:/FOO/BAR/BAZ").endsWith(new PathFragment("/bar/baz"))).isFalse();
+    assertThat(new PathFragment("c:/FOO/BAR/BAZ").endsWith(new PathFragment("d:\\bar\\baz")))
+        .isFalse();
+    // relativeTo
+    assertThat(new PathFragment("c:/FOO/BAR/BAZ/QUX").relativeTo(new PathFragment("c:\\foo\\bar")))
+        .isEqualTo(new PathFragment("Baz/Qux"));
+  }
+
+  @Test
+  public void testCaseInsensitiveRootedPath() {
+    Path ancestor = filesystem.getPath("C:\\foo\\bar");
+    assertThat(ancestor).isInstanceOf(WindowsPath.class);
+    Path child = filesystem.getPath("C:\\FOO\\Bar\\baz");
+    assertThat(child).isInstanceOf(WindowsPath.class);
+    assertThat(child.startsWith(ancestor)).isTrue();
+    assertThat(child.relativeTo(ancestor)).isEqualTo(new PathFragment("baz"));
+    RootedPath actual = RootedPath.toRootedPath(ancestor, child);
+    assertThat(actual.getRoot()).isEqualTo(ancestor);
+    assertThat(actual.getRelativePath()).isEqualTo(new PathFragment("baz"));
+  }
 }