Make Test Report locale independent (#868)

Format numbers with `.` decimals

pkl-cli/src/test/kotlin/org/pkl/cli/CliTestRunnerTest.kt

@@ -21,6 +21,7 @@ import java.io.StringWriter
 import java.io.Writer
 import java.net.URI
 import java.nio.file.Path
+import java.util.Locale
 import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.Assertions.assertThatCode
 import org.junit.jupiter.api.Test
@@ -487,6 +488,50 @@ class CliTestRunnerTest {
       )
   }
 
+  @Test
+  fun `CliTestRunner locale independence test`(@TempDir tempDir: Path) {
+    val originalLocale = Locale.getDefault()
+    Locale.setDefault(Locale.GERMANY)
+
+    try {
+      val code =
+        """
+        amends "pkl:test"
+
+        facts {
+            ["localeTest"] {
+                1 == 1
+            }
+        }
+        """
+          .trimIndent()
+      val input = tempDir.resolve("test.pkl").writeString(code).toString()
+      val out = StringWriter()
+      val err = StringWriter()
+      val opts =
+        CliBaseOptions(sourceModules = listOf(input.toUri()), settings = URI("pkl:settings"))
+      val testOpts = CliTestOptions()
+      val runner = CliTestRunner(opts, testOpts, consoleWriter = out, errWriter = err)
+      runner.run()
+
+      assertThat(out.toString().stripFileAndLines(tempDir))
+        .isEqualTo(
+          """
+            module test
+              facts
+                ✔ localeTest
+
+            100.0% tests pass [1 passed], 100.0% asserts pass [1 passed]
+
+            """
+            .trimIndent()
+        )
+      assertThat(err.toString()).isEqualTo("")
+    } finally {
+      Locale.setDefault(originalLocale)
+    }
+  }
+
   private fun String.stripFileAndLines(tmpDir: Path): String {
     // handle platform differences in handling of file URIs
     // (file:/// on *nix vs. file:/ on Windows)

pkl-core/src/main/java/org/pkl/core/stdlib/test/report/SimpleReport.java

@@ -18,6 +18,7 @@ package org.pkl.core.stdlib.test.report;
 import java.io.IOException;
 import java.io.Writer;
 import java.util.List;
+import java.util.Locale;
 import java.util.stream.Collectors;
 import org.pkl.core.TestResults;
 import org.pkl.core.TestResults.TestResult;
@@ -144,7 +145,10 @@ public final class SimpleReport implements TestReport {
     sb.append(
         color,
         () ->
-            sb.append(String.format("%.1f%%", passRate)).append(" ").append(kind).append(" pass"));
+            sb.append(String.format(Locale.ROOT, "%.1f%%", passRate))
+                .append(" ")
+                .append(kind)
+                .append(" pass"));
 
     if (isFailed) {
       sb.append(" [").append(failed).append('/').append(total).append(" failed]");