ScalaFmt takes filepath into consideration.

lib/src/scalafmt/java/com/diffplug/spotless/glue/scalafmt/ScalafmtFormatterFunc.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 DiffPlug
+ * Copyright 2022-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -51,4 +51,9 @@ public ScalafmtFormatterFunc(FileSignature configSignature) throws Exception {
 	public String apply(String input) {
 		return Scalafmt.format(input, config, Set$.MODULE$.empty()).get();
 	}
+
+	@Override
+	public String apply(String input, File file) {
+		return Scalafmt.format(input, config, Set$.MODULE$.empty(), file.getAbsolutePath()).get();
+	}
 }

testlib/src/main/java/com/diffplug/spotless/StepHarness.java

@@ -80,7 +80,11 @@ public StepHarness testUnaffected(String idempotentElement) {
 	public StepHarness testResource(String resourceBefore, String resourceAfter) {
 		String before = ResourceHarness.getTestResource(resourceBefore);
 		String after = ResourceHarness.getTestResource(resourceAfter);
-		return test(before, after);
+		String actual = formatter().compute(LineEnding.toUnix(before), new File(resourceBefore));
+		assertEquals(after, actual, "Step application failed");
+		actual = formatter().compute(LineEnding.toUnix(after), new File(resourceAfter));
+		assertEquals(after, actual, "Step is not idempotent");
+		return this;
 	}
 
 	/** Asserts that the given elements in the resources directory are transformed as expected. */

testlib/src/main/resources/scala/scalafmt/basic.dirty

@@ -1,4 +1,4 @@
-@ foobar("annot", {
+@foobar ("annot", {
   val x = 2
   val y = 2 // y=2
   x + y

testlib/src/main/resources/scala/scalafmt/scalafmt.fileoverride.conf

@@ -0,0 +1,9 @@
+version = 3.7.3
+runner.dialect = scala213
+style = defaultWithAlign # For pretty alignment.
+maxColumn = 200          # For my mega-wide display
+fileOverride {
+  "glob:**/scala/scalafmt/**" {
+    maxColumn = 20           # For my teensy narrow display
+  }
+}

testlib/src/test/java/com/diffplug/spotless/scala/ScalaFmtStepTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2023 DiffPlug
+ * Copyright 2016-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -40,6 +40,13 @@ void behaviorCustomConfig() {
 				.testResource("scala/scalafmt/basic.dirty", "scala/scalafmt/basic.cleanWithCustomConf_3.0.0");
 	}
 
+	@Test
+	void behaviorFileOverride() {
+		FormatterStep step = ScalaFmtStep.create(ScalaFmtStep.DEFAULT_VERSION, TestProvisioner.mavenCentral(), createTestFile("scala/scalafmt/scalafmt.fileoverride.conf"));
+		StepHarness.forStep(step)
+				.testResource("scala/scalafmt/basic.dirty", "scala/scalafmt/basic.cleanWithCustomConf_3.0.0");
+	}
+
 	@Test
 	void behaviorDefaultConfigVersion_3_0_0() {
 		FormatterStep step = ScalaFmtStep.create("3.0.0", TestProvisioner.mavenCentral(), null);