Add a test which exercises every branch of GitRatchet.

Author: nedtwigg

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/RatchetFromTest.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2016 DiffPlug
+ *
+ * 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.diffplug.gradle.spotless;
+
+import org.eclipse.jgit.api.Git;
+import org.junit.Test;
+
+public class RatchetFromTest extends GradleIntegrationTest {
+	@Test
+	public void singleProjectExhaustive() throws Exception {
+		Git git = Git.init().setDirectory(rootFolder()).call();
+		setFile("build.gradle").toLines(
+				"plugins {",
+				"  id 'com.diffplug.gradle.spotless'",
+				"}",
+				"spotless {",
+				"  ratchetFrom 'baseline'",
+				"  format 'misc', {",
+				"    target '*.md'",
+				"    custom 'lowercase', { str -> str.toLowerCase() }",
+				"    bumpThisNumberIfACustomStepChanges(1)",
+				"  }",
+				"}");
+		setFile("test.md").toContent("HELLO");
+		git.add().addFilepattern("test.md").call();
+		git.commit().setMessage("Initial state").call();
+		// tag this initial state as the baseline for spotless to ratchet from
+		git.tag().setName("baseline").call();
+
+		// so at this point we have test.md, and it would normally be dirty,
+		// but because it is unchanged, spotless says it is clean
+		assertClean();
+
+		// but if we change it so that it is not clean, spotless will now say it is dirty
+		setFile("test.md").toContent("HELLO WORLD");
+		assertDirty();
+		gradleRunner().withArguments("spotlessApply").build();
+		assertFile("test.md").hasContent("hello world");
+
+		// but if we make it unchanged again, it goes back to being clean
+		setFile("test.md").toContent("HELLO");
+		assertClean();
+
+		// and if we make the index dirty
+		setFile("test.md").toContent("HELLO WORLD");
+		git.add().addFilepattern("test.md").call();
+		{
+			// and the content dirty in the same way, then it's dirty
+			assertDirty();
+			// if we make the content something else dirty, then it's dirty
+			setFile("test.md").toContent("HELLO MOM");
+			assertDirty();
+			// if we make the content unchanged, even though index it and index are dirty, then it's clean
+			setFile("test.md").toContent("HELLO");
+			assertClean();
+			// if we delete the file, but it's still in the index, then it's clean
+			setFile("test.md").deleted();
+			assertClean();
+		}
+		// if we remove the file from the index
+		git.rm().addFilepattern("test.md").setCached(true).call();
+		{
+			// and it's gone in real life too, then it's clean
+			assertClean();
+			// if the content is there and unchanged, then it's clean
+			setFile("test.md").toContent("HELLO");
+			assertClean();
+			// if the content is dirty, then it's dirty
+			setFile("test.md").toContent("HELLO WORLD");
+			assertDirty();
+		}
+
+		// new files always get checked
+		setFile("new.md").toContent("HELLO");
+		{
+			assertDirty();
+			// even if they are added
+			git.add().addFilepattern("new.md").call();
+			assertDirty();
+		}
+	}
+
+	private void assertClean() throws Exception {
+		gradleRunner().withArguments("spotlessCheck").build();
+	}
+
+	private void assertDirty() throws Exception {
+		gradleRunner().withArguments("spotlessCheck").buildAndFail();
+	}
+}