fix: work around freshmark issues

dynamically created files that are not available at configuration time
proof to be a challenge.

Author: simschla

build-logic/src/main/groovy/buildlogic.spotless-markdown-conventions.gradle

@@ -1,3 +1,5 @@
+import com.diffplug.spotless.cli.picocli.usage.DocumentedUsages
+
 plugins {
 	id 'buildlogic.spotless-common-conventions'
 }
@@ -40,18 +42,35 @@ class FreshmarkPropertiesAction implements Action<Map<String, Object>> {
 		return versionsCollected
 	}
 
-	Map<String, String> getUsageHelps() {
-		Map<String, String> usageHelps = [:]
+	Map<String, Object> getUsageHelps() {
+		Map<String, Object> usageHelps = [:]
 		File outputDir = rootProject.file("app/build/generated-usages")
-		File[] usageFiles = outputDir.listFiles()
 
-		usageFiles.each { usageFile ->
-			String usage = asJsArrayOfLines(usageFile.readLines())
-			String name = usageFile.name.substring(0, usageFile.name.indexOf('.'))
-			usageHelps.put("usage.${name}.array".toString(), usage)
+		DocumentedUsages.values().each { usage ->
+			File usageFile = new File(outputDir, usage.fileName)
+			usageHelps.put("usage.${usage.formatterStepName}.array".toString(), new UsageHelp(usageFile))
 		}
 		return usageHelps
 	}
+}
+
+
+class UsageHelp implements Serializable {
+
+	private final File usageFile
+
+	UsageHelp(File usageFile) {
+		this.usageFile = usageFile
+	}
+
+	@Override
+	String toString() {
+		if (usageFile.canRead()) {
+			return asJsArrayOfLines(usageFile.readLines())
+		}
+		return '[]'
+	}
+
 
 	private static String asJsArrayOfLines(List<String> lines) {
 		return '[' +
@@ -67,4 +86,5 @@ class FreshmarkPropertiesAction implements Action<Map<String, Object>> {
 
 tasks.named('spotlessFreshmark').configure {
 	dependsOn(':app:generateUsage') // to make sure usage files are generated before spotlessFreshmark
+	inputs.files(rootProject.project(':app').tasks.named('generateUsage').get().inputs.files)
 }

build-logic/src/main/groovy/com/diffplug/spotless/cli/picocli/usage/DocumentedUsages.groovy

@@ -0,0 +1,38 @@
+package com.diffplug.spotless.cli.picocli.usage
+
+enum DocumentedUsages {
+
+	MAIN(""),
+	GOOGLE_JAVA_FORMAT(),
+	LICENSE_HEADER(),
+	PRETTIER()
+
+	private final String fileName
+
+	private final String formatterStepName
+
+	DocumentedUsages(){
+		this(null)
+	}
+
+	DocumentedUsages(String formatterStepName){
+		this.formatterStepName = formatterStepName ?: name().toLowerCase().replace('_', '-')
+		this.fileName = "${name().toLowerCase().replace('_', '-')}.spotless.usage.txt"
+	}
+
+	String getFileName() {
+		return fileName
+	}
+
+	String getFormatterStepName() {
+		return formatterStepName
+	}
+
+	static List<String> getFormatterNames() {
+		return values().collect { it.formatterStepName }
+	}
+
+	static List<String> getFileNames() {
+		return values().collect { it.fileName }
+	}
+}

build-logic/src/main/groovy/com/diffplug/spotless/cli/picocli/usage/GenerateUsagePropertiesTask.groovy

@@ -47,10 +47,7 @@ abstract class GenerateUsagePropertiesTask extends DefaultTask {
 		// remove all files from outputDir if any
 		outputDir.get().deleteDir()
 
-		String mainUsage = getUsage("")
-		writeUsageFile(mainUsage, "main")
-
-		List<String> formatterNames = findFormatterNamesFromClasspath()
+		List<String> formatterNames = DocumentedUsages.formatterNames
 		Map<String, String> formatterUsages = [:]
 		formatterNames.each { formatterName ->
 			formatterUsages.put(formatterName, getUsage(formatterName))
@@ -61,17 +58,6 @@ abstract class GenerateUsagePropertiesTask extends DefaultTask {
 		}
 	}
 
-	List<String> findFormatterNamesFromClasspath() {
-		ClasspathScanner scanner = new ClasspathScanner(runtimeClasspath.get(), { String clazzName -> clazzName.contains("com.diffplug.spotless.cli")})
-		CommandInfoReader commandInfoReader = new CommandInfoReader(scanner.withoutClassFilter())
-		List<Class<?>> formatterClasses = scanner.findInstancesOf("com.diffplug.spotless.cli.steps.SpotlessCLIFormatterStep")
-		List<String> formatterNames = []
-		for (Class<?> formatterClass : formatterClasses) {
-			formatterNames << commandInfoReader.readCommandName(formatterClass)
-		}
-		return formatterNames
-	}
-
 	String getUsage(String formatterName) {
 		ByteArrayOutputStream output = new ByteArrayOutputStream()
 		ExecResult result = execOperations.javaexec {