props: support pre-escaped unicode (#341)

Author: itzg

src/main/java/me/itzg/helpers/properties/SetPropertiesCommand.java

@@ -16,13 +16,15 @@
 import java.util.Objects;
 import java.util.Properties;
 import java.util.concurrent.Callable;
+import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import lombok.Setter;
 import lombok.extern.slf4j.Slf4j;
 import me.itzg.helpers.env.EnvironmentVariablesProvider;
 import me.itzg.helpers.env.StandardEnvironmentVariablesProvider;
 import me.itzg.helpers.errors.InvalidParameterException;
 import me.itzg.helpers.json.ObjectMappers;
+import org.jetbrains.annotations.NotNull;
 import picocli.CommandLine.Command;
 import picocli.CommandLine.ExitCode;
 import picocli.CommandLine.Option;
@@ -54,6 +56,8 @@ public class SetPropertiesCommand implements Callable<Integer> {
     @Setter
     private EnvironmentVariablesProvider environmentVariablesProvider = new StandardEnvironmentVariablesProvider();
 
+    private static final Pattern UNICODE_ESCAPE = Pattern.compile("\\\\u([0-9a-fA-F]{4})");
+
     @Override
     public Integer call() throws Exception {
         if (propertyDefinitionsFile == null && customProperties == null) {
@@ -204,6 +208,25 @@ private String mapAndValidateValue(PropertyDefinition definition, String value)
                 );
             }
         }
-        return value;
+
+        return unescapeUnicode(value);
+    }
+
+    @NotNull
+    private static String unescapeUnicode(String value) {
+        final Matcher m = UNICODE_ESCAPE.matcher(value);
+        if (m.find()) {
+            StringBuffer sb = new StringBuffer();
+            do {
+                final int charValue = Integer.parseUnsignedInt(m.group(1), 16);
+                m.appendReplacement(sb, ""+(char)charValue);
+            } while (m.find());
+            m.appendTail(sb);
+
+            return sb.toString();
+        }
+        else {
+            return value;
+        }
     }
 }

src/test/java/me/itzg/helpers/properties/SetPropertiesCommandTest.java

@@ -219,6 +219,29 @@ void encodesWithGivenEncoding() {
 
     }
 
+    @Test
+    void encodesPreEscaped() {
+        final Path outputProperties = tempDir.resolve("out.properties");
+
+        final int exitCode = new CommandLine(new SetPropertiesCommand()
+            .setEnvironmentVariablesProvider(MappedEnvVarProvider.of(
+                "LEVEL_NAME", "sv\\u011Bt"
+            ))
+        )
+            .execute(
+                "--definitions", definitionsFile.toString(),
+                outputProperties.toString()
+            );
+
+        assertThat(exitCode).isEqualTo(ExitCode.OK);
+
+        //noinspection UnnecessaryUnicodeEscape
+        assertThat(outputProperties)
+            .content(StandardCharsets.UTF_8)
+            .containsIgnoringNewLines("level-name=svět");
+
+    }
+
     private void assertPropertiesEqualExcept(Properties properties, String... propertiesToIgnore) {
         final HashSet<Object> actualKeys = new HashSet<>(properties.keySet());
         Arrays.asList(propertiesToIgnore).forEach(actualKeys::remove);