feat: allow checksum-calculation for string

Author: simschla

app/src/main/java/com/diffplug/spotless/cli/core/ChecksumCalculator.java

@@ -37,6 +37,11 @@
 
 public class ChecksumCalculator {
 
+    public String calculateChecksum(String text) {
+        byte[] bytes = text.getBytes(StandardCharsets.UTF_8);
+        return toHashedHexBytes(bytes);
+    }
+
     public String calculateChecksum(SpotlessCLIFormatterStep step) {
         try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
             writeObjectDataTo(step, out);

app/src/test/java/com/diffplug/spotless/cli/core/ChecksumCalculatorTest.java

@@ -25,6 +25,7 @@
 import org.jetbrains.annotations.NotNull;
 import org.junit.jupiter.api.Test;
 
+import com.diffplug.selfie.Selfie;
 import com.diffplug.spotless.FormatterStep;
 import com.diffplug.spotless.cli.SpotlessAction;
 import com.diffplug.spotless.cli.SpotlessActionContextProvider;
@@ -190,6 +191,16 @@ void itCalculatesDifferentChecksumDueToDifferentSetterOption() {
         assertThat(checksum1).isNotEqualTo(checksum2);
     }
 
+    @Test
+    void itCalculatesChecksumForFilePath() {
+        Path testPath = Path.of("var", "tmp", "test.txt");
+
+        String checksum =
+                checksumCalculator.calculateChecksum(testPath.toAbsolutePath().toString());
+
+        Selfie.expectSelfie(checksum).toBe("ef184d3abbb8db0a9867f9abaae87397");
+    }
+
     private static Step step(
             Path test1, String test2, StepArgGroup argGroup, StepArgGroup argGroup2, List<Path> parameters) {
         return step(test1, test2, test1 + test2, argGroup, argGroup2, parameters);