refactor: move test runners and baseclasses to testlib

Author: simschla

testlib/build.gradle

@@ -5,4 +5,5 @@ plugins {
 dependencies {
 	implementation libs.bundles.test.libs
 	implementation libs.bundles.durian.libs
+	implementation libs.picocli
 }

…/spotless/cli/CLIIntegrationHarness.java …/spotless/cli/CLIIntegrationHarness.javaapp/src/test/java/com/diffplug/spotless/cli/CLIIntegrationHarness.java renamed to testlib/src/main/java/com/diffplug/spotless/cli/CLIIntegrationHarness.java app/src/test/java/com/diffplug/spotless/cli/CLIIntegrationHarness.java renamed to testlib/src/main/java/com/diffplug/spotless/cli/CLIIntegrationHarness.java

@@ -23,7 +23,7 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import com.diffplug.spotless.cli.steps.SpotlessCLIFormatterStep;
+import com.diffplug.spotless.ThrowingEx;
 
 import picocli.CommandLine;
 
@@ -76,12 +76,25 @@ public SpotlessCLIRunner withStep(@NotNull String stepName) {
         return this;
     }
 
-    public SpotlessCLIRunner withStep(@NotNull Class<? extends SpotlessCLIFormatterStep> stepClass) {
+    /**
+     * Adds a step to the command line arguments.
+     * The step class must implement {@link SpotlessCLIFormatterStep}.
+     *
+     * @param stepClass the class of the step to add
+     * @return this instance for method chaining
+     * @throws IllegalArgumentException if the step class does not implement {@link SpotlessCLIFormatterStep}
+     */
+    public SpotlessCLIRunner withStep(@NotNull Class<?> stepClass) {
+        // use reflection to allow having this class in testlib
+        if (!ThrowingEx.get(() -> Class.forName("com.diffplug.spotless.cli.steps.SpotlessCLIFormatterStep"))
+                .isAssignableFrom(stepClass)) {
+            throw new IllegalArgumentException("Step class must implement SpotlessCLIFormatterStep");
+        }
         String stepName = determineStepName(stepClass);
         return withStep(stepName);
     }
 
-    private String determineStepName(Class<? extends SpotlessCLIFormatterStep> stepClass) {
+    private String determineStepName(Class<?> stepClass) {
         CommandLine.Command annotation = stepClass.getAnnotation(CommandLine.Command.class);
         if (annotation == null) {
             throw new IllegalArgumentException("Step class must be annotated with @CommandLine.Command");

…plug/spotless/cli/SpotlessCLIRunner.java …plug/spotless/cli/SpotlessCLIRunner.javaapp/src/test/java/com/diffplug/spotless/cli/SpotlessCLIRunner.java renamed to testlib/src/main/java/com/diffplug/spotless/cli/SpotlessCLIRunner.java app/src/test/java/com/diffplug/spotless/cli/SpotlessCLIRunner.java renamed to testlib/src/main/java/com/diffplug/spotless/cli/SpotlessCLIRunner.java

@@ -19,15 +19,16 @@
 import java.io.StringWriter;
 import java.util.List;
 
+import com.diffplug.spotless.ThrowingEx;
+
 import picocli.CommandLine;
 
 public class SpotlessCLIRunnerInSameThread extends SpotlessCLIRunner {
 
     static final String SPOTLESS_CLI_IN_SAME_THREAD = "spotless.cli.inSameThread";
 
     protected Result executeCommand(List<String> args) {
-        SpotlessCLI cli = SpotlessCLI.createInstance();
-        CommandLine commandLine = SpotlessCLI.createCommandLine(cli);
+        CommandLine commandLine = createCommandLine();
 
         StringWriter out = new StringWriter();
         StringWriter err = new StringWriter();
@@ -51,6 +52,15 @@ protected Result executeCommand(List<String> args) {
         }
     }
 
+    private static CommandLine createCommandLine() {
+        return ThrowingEx.get(() -> {
+            Class<?> cliClass = Class.forName("com.diffplug.spotless.cli.SpotlessCLI");
+            Object cliInstance = cliClass.getDeclaredMethod("createInstance").invoke(null);
+            return (CommandLine)
+                    cliClass.getDeclaredMethod("createCommandLine", cliClass).invoke(null, cliClass.cast(cliInstance));
+        });
+    }
+
     private String[] argsWithBaseDir(List<String> args) {
         // prepend the base dir
         String[] argsWithBaseDir = new String[args.size() + 2];