Add support for git's core.autocrlf

CHANGES.md

@@ -15,6 +15,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * Bump default versions of formatters ([#1095](https://github.com/diffplug/spotless/pull/1095)).
   * google-java-format `1.12.0` -> `1.13.0`
   * ktfmt `0.29` -> `0.30`
+* Added support for git property `core.autocrlf` ([#540](https://github.com/diffplug/spotless/issues/540))
 
 ## [2.22.0] - 2022-01-13
 ### Added

lib-extra/src/main/java/com/diffplug/spotless/extra/GitAttributesLineEndings.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 DiffPlug
+ * Copyright 2016-2022 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,6 +38,7 @@
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.CoreConfig.AutoCRLF;
 import org.eclipse.jgit.lib.CoreConfig.EOL;
 import org.eclipse.jgit.storage.file.FileBasedConfig;
 import org.eclipse.jgit.storage.file.FileRepositoryBuilder;
@@ -56,7 +57,7 @@
 
 /**
  * Uses <a href="https://git-scm.com/docs/gitattributes">.gitattributes</a> to determine
- * the appropriate line ending. Falls back to the {@code core.eol} property in the
+ * the appropriate line ending. Falls back to the {@code core.eol} and {@code core.autocrlf} properties in the
  * git config if there are no applicable git attributes, then finally falls
  * back to the platform native.
  */
@@ -224,7 +225,7 @@ static class Runtime {
 		private Runtime(List<AttributesRule> infoRules, @Nullable File workTree, Config config, List<AttributesRule> globalRules) {
 			this.infoRules = Objects.requireNonNull(infoRules);
 			this.workTree = workTree;
-			this.defaultEnding = fromEol(config.getEnum(ConfigConstants.CONFIG_CORE_SECTION, null, ConfigConstants.CONFIG_KEY_EOL, EOL.NATIVE)).str();
+			this.defaultEnding = findDefaultLineEnding(config).str();
 			this.globalRules = Objects.requireNonNull(globalRules);
 		}
 
@@ -273,6 +274,28 @@ private static String convertEolToLineEnding(String eol, File file) {
 			}
 		}
 
+		private LineEnding findDefaultLineEnding(Config config) {
+			// handle core.autocrlf, whose values "true" and "input" override core.eol
+			AutoCRLF autoCRLF = config.getEnum(ConfigConstants.CONFIG_CORE_SECTION, null, ConfigConstants.CONFIG_KEY_AUTOCRLF, AutoCRLF.FALSE);
+			if (autoCRLF == AutoCRLF.TRUE) {
+				// autocrlf=true converts CRLF->LF during commit
+				//               and converts LF->CRLF during checkout
+				// so CRLF is the default line ending
+				return LineEnding.WINDOWS;
+			} else if (autoCRLF == AutoCRLF.INPUT) {
+				// autocrlf=input converts CRLF->LF during commit
+				//                and does no conversion during checkout
+				// mostly used on Unix, so LF is the default encoding
+				return LineEnding.UNIX;
+			} else if (autoCRLF == AutoCRLF.FALSE) {
+				// handle core.eol
+				EOL eol = config.getEnum(ConfigConstants.CONFIG_CORE_SECTION, null, ConfigConstants.CONFIG_KEY_EOL, EOL.NATIVE);
+				return fromEol(eol);
+			} else {
+				throw new IllegalStateException("Unexpected value for autoCRLF " + autoCRLF);
+			}
+		}
+
 		/** Creates a LineEnding from an EOL. */
 		private static LineEnding fromEol(EOL eol) {
 			// @formatter:off

lib-extra/src/test/java/com/diffplug/spotless/extra/GitAttributesTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 DiffPlug
+ * Copyright 2016-2022 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,8 @@
 import java.util.List;
 
 import org.assertj.core.api.Assertions;
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.errors.GitAPIException;
 import org.junit.jupiter.api.Test;
 
 import com.diffplug.common.base.Errors;
@@ -87,4 +89,16 @@ void policyTest() throws IOException {
 		Assertions.assertThat(policy.getEndingFor(newFile("MANIFEST.MF"))).isEqualTo("\r\n");
 		Assertions.assertThat(policy.getEndingFor(newFile("subfolder/MANIFEST.MF"))).isEqualTo("\r\n");
 	}
+
+	@Test
+	void policyDefaultLineEndingTest() throws GitAPIException, IOException {
+		Git git = Git.init().setDirectory(rootFolder()).call();
+		git.close();
+		setFile(".git/config").toContent(StringPrinter.buildStringFromLines(
+				"[core]",
+				"autocrlf=true",
+				"eol=lf"));
+		LineEnding.Policy policy = LineEnding.GIT_ATTRIBUTES.createPolicy(rootFolder(), () -> testFiles());
+		Assertions.assertThat(policy.getEndingFor(newFile("someFile"))).isEqualTo("\r\n");
+	}
 }

plugin-gradle/CHANGES.md

@@ -7,6 +7,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * Bump default versions of formatters ([#1095](https://github.com/diffplug/spotless/pull/1095)).
   * google-java-format `1.12.0` -> `1.13.0`
   * ktfmt `0.29` -> `0.30`
+* Added support for git property `core.autocrlf` ([#540](https://github.com/diffplug/spotless/issues/540))
 
 ## [6.2.0] - 2022-01-13
 ### Added

plugin-maven/CHANGES.md

@@ -6,6 +6,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * Bump default versions of formatters ([#1095](https://github.com/diffplug/spotless/pull/1095)).
   * google-java-format `1.12.0` -> `1.13.0`
   * ktfmt `0.29` -> `0.30`
+* Added support for git property `core.autocrlf` ([#540](https://github.com/diffplug/spotless/issues/540))
 
 ## [2.20.0] - 2022-01-13
 ### Added