GH-3289: Test CLI help, version and error handling

parquet-cli/src/test/java/org/apache/parquet/cli/CliBehaviorTest.java

@@ -0,0 +1,135 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.parquet.cli;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.nio.file.Path;
+import org.apache.parquet.Version;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+class CliBehaviorTest extends CliTestBase {
+
+  @ParameterizedTest
+  @ValueSource(strings = {"help", "-h", "-help", "--help"})
+  void printsGeneralHelp(String command) throws Exception {
+    CliResult result = cli(command);
+
+    assertThat(result.exitCode()).isZero();
+    assertThat(result.output())
+        .contains("Usage: parquet [options] [command] [command options]", "Commands:", "schema", "meta");
+    assertThat(result.output()).doesNotContain("--dollar-zero");
+  }
+
+  @Test
+  void printsCommandHelp() throws Exception {
+    CliResult result = cli("help", "schema");
+
+    assertThat(result.exitCode()).isZero();
+    assertThat(result.output()).contains("Usage: parquet [general options] schema", "--output", "--overwrite");
+    assertThat(result.output()).doesNotContain("Commands:");
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"-h", "-help", "--help"})
+  void printsHelpAfterCommand(String option) throws Exception {
+    CliResult result = cli("rewrite", option);
+
+    assertThat(result.exitCode()).isZero();
+    assertThat(result.output()).contains("Usage: parquet [general options] rewrite", "--input", "--output");
+    assertThat(result.output()).doesNotContain("Argument error");
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"version", "-version", "--version"})
+  void printsVersion(String command) throws Exception {
+    CliResult result = cli(command);
+
+    assertThat(result.exitCode()).isZero();
+    assertThat(result.output()).isEqualTo(Version.FULL_VERSION);
+  }
+
+  @Test
+  void printsHelpAndFailsWithoutCommand() throws Exception {
+    CliResult result = cli();
+
+    assertThat(result.exitCode()).isEqualTo(1);
+    assertThat(result.output()).contains("Usage: parquet [options] [command] [command options]");
+  }
+
+  @Test
+  void rejectsUnknownCommand() throws Exception {
+    CliResult result = cli("not-a-command");
+
+    assertThat(result.exitCode()).isEqualTo(1);
+    assertThat(result.output()).contains("not-a-command");
+  }
+
+  @Test
+  void rejectsHelpForUnknownCommand() throws Exception {
+    CliResult result = cli("help", "not-a-command");
+
+    assertThat(result.exitCode()).isEqualTo(1);
+    assertThat(result.output()).contains("Unknown command: not-a-command", "Usage: parquet");
+  }
+
+  @Test
+  void rejectsUnknownOption() throws Exception {
+    CliResult result = cli("rewrite", "--not-an-option");
+
+    assertThat(result.exitCode()).isEqualTo(1);
+    assertThat(result.output()).contains("--not-an-option");
+  }
+
+  @Test
+  void rejectsMissingOptionValue() throws Exception {
+    CliResult result = cli("schema", "--output");
+
+    assertThat(result.exitCode()).isEqualTo(1);
+    assertThat(result.output()).contains("--output");
+  }
+
+  @Test
+  void rejectsMissingInput() throws Exception {
+    CliResult result = cli("schema");
+
+    assertThat(result.exitCode()).isEqualTo(1);
+    assertThat(result.output()).contains("Argument error: Parquet file is required.");
+  }
+
+  @Test
+  void printsCommandHelpForMissingRequiredOptions() throws Exception {
+    CliResult result = cli("rewrite");
+
+    assertThat(result.exitCode()).isEqualTo(1);
+    assertThat(result.output()).contains("Usage: parquet [general options] rewrite", "--input", "--output");
+  }
+
+  @Test
+  void reportsMissingInputFile() throws Exception {
+    Path input = getTempFolder().toPath().resolve("missing input.parquet");
+
+    CliResult result = cli("schema", input.toString());
+
+    assertThat(result.exitCode()).isEqualTo(1);
+    assertThat(result.output()).contains("Unknown error", "FileNotFoundException", "missing input.parquet");
+  }
+}