add test for min version check + adapt others

Author: simschla

lib/src/main/java/com/diffplug/spotless/Jvm.java

@@ -152,7 +152,7 @@ private String buildUnsupportedFormatterMessage(V fmtVersion) {
 			// check if the formatter version is too low for the jvm version
 			V minimumFormatterVersion = getMinimumRequiredFormatterVersion();
 			if ((null != minimumFormatterVersion) && (fmtVersionComparator.compare(fmtVersion, minimumFormatterVersion) < 0)) {
-				return String.format("You are running Spotless on JVM %d, which requires %s of at least %s (you are using %s).%n", Jvm.version(), fmtName, minimumFormatterVersion, fmtVersion);
+				return String.format("You are running Spotless on JVM %d. This requires %s of at least %s (you are using %s).%n", Jvm.version(), fmtName, minimumFormatterVersion, fmtVersion);
 			}
 			// otherwise all is well
 			return "";
@@ -228,7 +228,7 @@ private String buildUpgradeFormatterMessage(V fmtVersion) {
 			V minimumFormatterVersion = getMinimumRequiredFormatterVersion();
 			V recommendedFmtVersionOrNull = getRecommendedFormatterVersion();
 			if ((null != minimumFormatterVersion) && (fmtVersionComparator.compare(fmtVersion, minimumFormatterVersion) < 0)) {
-				builder.append(String.format("You are running Spotless on JVM %d, which requires %s of at least %s.%n", Jvm.version(), fmtName, minimumFormatterVersion));
+				builder.append(String.format("You are running Spotless on JVM %d. This requires %s of at least %s.%n", Jvm.version(), fmtName, minimumFormatterVersion));
 				builder.append(String.format("You are using %s %s.%n", fmtName, fmtVersion));
 				if (null != recommendedFmtVersionOrNull) {
 					builder.append(String.format("%s %s is the recommended version, which may have fixed this problem.%n", fmtName, recommendedFmtVersionOrNull));

lib/src/main/java/com/diffplug/spotless/java/GoogleJavaFormatStep.java

@@ -70,7 +70,7 @@ public static FormatterStep create(String groupArtifact, String version, String
 	}
 
 	static final Jvm.Support<String> JVM_SUPPORT = Jvm.<String> support(NAME)
-			.addMin(11, "1.8") // spotless requires java 11, so the min version of google java format we can support is 1.8
+			.addMin(11, "1.8") // we only support google-java-format >= 1.8 due to api changes
 			.add(11, "1.15.0"); // default version
 
 	public static String defaultGroupArtifact() {

testlib/src/main/resources/java/googlejavaformat/JavaCodeFormatted.test

@@ -1,4 +1,3 @@
-
 import mylib.UsedA;
 import mylib.UsedB;
 

testlib/src/main/resources/java/googlejavaformat/JavaCodeFormattedAOSP.test

@@ -1,4 +1,3 @@
-
 import mylib.UsedA;
 import mylib.UsedB;
 

testlib/src/test/java/com/diffplug/spotless/java/GoogleJavaFormatStepTest.java

@@ -51,7 +51,7 @@ void behavior18() throws Exception {
 
 	@Test
 	void behavior() throws Exception {
-		FormatterStep step = GoogleJavaFormatStep.create("1.2", TestProvisioner.mavenCentral());
+		FormatterStep step = GoogleJavaFormatStep.create("1.8", TestProvisioner.mavenCentral());
 		StepHarness.forStep(step)
 				.testResource("java/googlejavaformat/JavaCodeUnformatted.test", "java/googlejavaformat/JavaCodeFormatted.test")
 				.testResource("java/googlejavaformat/JavaCodeWithLicenseUnformatted.test", "java/googlejavaformat/JavaCodeWithLicenseFormatted.test")
@@ -60,8 +60,16 @@ void behavior() throws Exception {
 	}
 
 	@Test
-	void behaviorWithAospStyle() throws Exception {
+	void versionBelowMinimumRequiredVersionIsNotAllowed() throws Exception {
 		FormatterStep step = GoogleJavaFormatStep.create("1.2", "AOSP", TestProvisioner.mavenCentral());
+		StepHarness.forStep(step)
+				.testResourceExceptionMsg("java/googlejavaformat/JavaCodeWithLicenseUnformatted.test")
+				.contains("you are using 1.2");
+	}
+
+	@Test
+	void behaviorWithAospStyle() throws Exception {
+		FormatterStep step = GoogleJavaFormatStep.create("1.8", "AOSP", TestProvisioner.mavenCentral());
 		StepHarness.forStep(step)
 				.testResource("java/googlejavaformat/JavaCodeUnformatted.test", "java/googlejavaformat/JavaCodeFormattedAOSP.test")
 				.testResource("java/googlejavaformat/JavaCodeWithLicenseUnformatted.test", "java/googlejavaformat/JavaCodeWithLicenseFormattedAOSP.test")
@@ -83,7 +91,7 @@ void behaviorWithReflowLongStrings() throws Exception {
 
 	@Test
 	void behaviorWithCustomGroupArtifact() throws Exception {
-		FormatterStep step = GoogleJavaFormatStep.create(GoogleJavaFormatStep.defaultGroupArtifact(), "1.2", GoogleJavaFormatStep.defaultStyle(), TestProvisioner.mavenCentral(), false);
+		FormatterStep step = GoogleJavaFormatStep.create(GoogleJavaFormatStep.defaultGroupArtifact(), "1.8", GoogleJavaFormatStep.defaultStyle(), TestProvisioner.mavenCentral(), false);
 		StepHarness.forStep(step)
 				.testResource("java/googlejavaformat/JavaCodeUnformatted.test", "java/googlejavaformat/JavaCodeFormatted.test")
 				.testResource("java/googlejavaformat/JavaCodeWithLicenseUnformatted.test", "java/googlejavaformat/JavaCodeWithLicenseFormatted.test")
@@ -94,7 +102,7 @@ void behaviorWithCustomGroupArtifact() throws Exception {
 	@Test
 	void equality() throws Exception {
 		new SerializableEqualityTester() {
-			String version = "1.2";
+			String version = "1.8";
 			String style = "";
 			boolean reflowLongStrings = false;
 
@@ -103,7 +111,7 @@ protected void setupTest(API api) {
 				// same version == same
 				api.areDifferentThan();
 				// change the version, and it's different
-				version = "1.1";
+				version = "1.9";
 				api.areDifferentThan();
 				// change the style, and it's different
 				style = "AOSP";