Add csv output format to validate and diff command

You can now pass `--format text|csv` to the validate and diff commands
to get CSV or text output. Text continues to be the default when not
specified.

This commit also updates the diff command to now correctly output
events to stdout rather than stderr.

smithy-cli/src/it/java/software/amazon/smithy/cli/DiffCommandTest.java

@@ -71,6 +71,24 @@ public void showsLabelForNewModelEvents() {
         });
     }
 
+    @Test
+    public void canWriteCsvOutput() {
+        IntegUtils.withTempDir("diff", dir -> {
+            Path a = dir.resolve("a.smithy");
+            writeFile(a, "$version: \"2.0\"\nnamespace example\nstring A\n");
+
+            Path b = dir.resolve("b.smithy");
+            writeFile(b, "$version: \"2.0\"\nnamespace example\n@aaaaaa\nstring A\n");
+
+            RunResult result = IntegUtils.run(dir, ListUtils.of("diff", "--old", a.toString(),
+                                                                "--new", b.toString(),
+                                                                "--format", "csv"));
+            assertThat("Not 1: output [" + result.getOutput() + ']', result.getExitCode(), is(1));
+            assertThat(result.getOutput(), containsString("severity,id,"));
+            assertThat(result.getOutput(), containsString("ERROR"));
+        });
+    }
+
     @Test
     public void showsLabelForDiffEvents() {
         IntegUtils.withTempDir("diff", dir -> {

smithy-cli/src/main/java/software/amazon/smithy/cli/commands/DiffCommand.java

@@ -67,6 +67,7 @@ public int execute(Arguments arguments, Env env) {
         arguments.addReceiver(new ConfigOptions());
         arguments.addReceiver(new ValidatorOptions());
         arguments.addReceiver(new BuildOptions());
+        arguments.addReceiver(new ValidationEventFormatOptions());
         arguments.addReceiver(new Options());
         arguments.getReceiver(BuildOptions.class).noPositionalArguments(true);
 
@@ -314,7 +315,7 @@ protected final ModelBuilder createModelBuilder(SmithyBuildConfig config, Argume
                     .config(config)
                     .arguments(arguments)
                     .env(env)
-                    .validationPrinter(env.stderr())
+                    .validationPrinter(env.stdout())
                     // Only report issues that fail the build.
                     .validationMode(Validator.Mode.QUIET_CORE_ONLY)
                     .defaultSeverity(Severity.DANGER);
@@ -326,6 +327,7 @@ protected final Model createNewModel(ModelBuilder builder, List<String> models,
                     .models(models)
                     .titleLabel("NEW", ColorTheme.DIFF_EVENT_TITLE)
                     .config(config)
+                    .disableOutputFormatFraming(true) // don't repeat things like CSV headers.
                     .build();
         }
 
@@ -337,6 +339,7 @@ protected final void runDiff(ModelBuilder builder, Env env, Model oldModel, Mode
                     .titleLabel("DIFF", ColorTheme.DIFF_TITLE)
                     .validatedResult(new ValidatedResult<>(newModel, events))
                     .defaultSeverity(null) // reset so it takes on standard option settings.
+                    .disableOutputFormatFraming(true) // don't repeat things like CSV headers.
                     .build();
         }
 

smithy-cli/src/main/java/software/amazon/smithy/cli/commands/ModelBuilder.java

@@ -61,10 +61,31 @@ final class ModelBuilder {
     private ValidatedResult<Model> validatedResult;
     private String titleLabel;
     private Style[] titleLabelStyles;
+    private ValidationEventFormatOptions.Format validationOutputFormat;
+    private boolean disableOutputFormatFraming = false;
     private boolean disableConfigModels;
 
     public ModelBuilder arguments(Arguments arguments) {
         this.arguments = arguments;
+
+        // Determine how to format the output, whether it's text (the default) or CSV.
+        // Only some commands (like validate) actually let you customize the output format, so assume a default.
+        if (validationOutputFormat == null) {
+            validationOutputFormat(arguments.hasReceiver(ValidationEventFormatOptions.class)
+                    ? arguments.getReceiver(ValidationEventFormatOptions.class).format()
+                    : ValidationEventFormatOptions.Format.TEXT);
+        }
+
+        return this;
+    }
+
+    public ModelBuilder disableOutputFormatFraming(boolean disableOutputFormatFraming) {
+        this.disableOutputFormatFraming = disableOutputFormatFraming;
+        return this;
+    }
+
+    public ModelBuilder validationOutputFormat(ValidationEventFormatOptions.Format validationOutputFormat) {
+        this.validationOutputFormat = validationOutputFormat;
         return this;
     }
 
@@ -180,14 +201,22 @@ public Model build() {
                 .titleLabel(titleLabel, titleLabelStyles)
                 .build();
 
+        if (!disableOutputFormatFraming) {
+            validationOutputFormat.beginPrinting(validationPrinter);
+        }
+
         for (ValidationEvent event : sortedEvents) {
             // Only log events that are >= --severity. Note that setting --quiet inherently
             // configures events to need to be >= DANGER. Also filter using --show-validators and --hide-validators.
             if (validatorOptions.isVisible(event)) {
-                validationPrinter.println(formatter.format(event));
+                validationOutputFormat.print(validationPrinter, formatter, event);
             }
         }
 
+        if (!disableOutputFormatFraming) {
+            validationOutputFormat.endPrinting(validationPrinter);
+        }
+
         env.flush();
         // Note: disabling validation will still show a summary of failures if the model can't be loaded.
         Validator.validate(validationMode != Validator.Mode.ENABLE, colors, stderr, validatedResult);

smithy-cli/src/main/java/software/amazon/smithy/cli/commands/ValidateCommand.java

@@ -48,6 +48,7 @@ public int execute(Arguments arguments, Env env) {
         arguments.addReceiver(new DiscoveryOptions());
         arguments.addReceiver(new ValidatorOptions());
         arguments.addReceiver(new BuildOptions());
+        arguments.addReceiver(new ValidationEventFormatOptions());
 
         CommandAction action = HelpActionWrapper.fromCommand(
             this,

smithy-cli/src/main/java/software/amazon/smithy/cli/commands/ValidationEventFormatOptions.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.cli.commands;
+
+import java.util.function.Consumer;
+import software.amazon.smithy.cli.ArgumentReceiver;
+import software.amazon.smithy.cli.CliError;
+import software.amazon.smithy.cli.CliPrinter;
+import software.amazon.smithy.cli.HelpPrinter;
+import software.amazon.smithy.model.shapes.ShapeId;
+import software.amazon.smithy.model.validation.ValidationEvent;
+import software.amazon.smithy.model.validation.ValidationEventFormatter;
+
+final class ValidationEventFormatOptions implements ArgumentReceiver {
+
+    private static final String VALIDATION_FORMAT = "--format";
+
+    enum Format {
+        TEXT {
+            @Override
+            void print(CliPrinter printer, ValidationEventFormatter formatter, ValidationEvent event) {
+                printer.println(formatter.format(event));
+            }
+        },
+
+        CSV {
+            @Override
+            void beginPrinting(CliPrinter printer) {
+                printer.println("severity,id,shape,file,message,hint,suppressionReason");
+            }
+
+            @Override
+            void print(CliPrinter printer, ValidationEventFormatter formatter, ValidationEvent event) {
+                printer.println(
+                        String.format("\"%s\",\"%s\",\"%s\",\"%s\",%d,%d,\"%s\",\"%s\",\"%s\"",
+                                      event.getSeverity().toString(),
+                                      formatCsv(event.getId()),
+                                      event.getShapeId().map(ShapeId::toString).orElse(""),
+                                      formatCsv(event.getSourceLocation().getFilename()),
+                                      event.getSourceLocation().getLine(),
+                                      event.getSourceLocation().getColumn(),
+                                      formatCsv(event.getMessage()),
+                                      formatCsv(event.getHint().orElse("")),
+                                      formatCsv(event.getSuppressionReason().orElse(""))));
+            }
+        };
+
+        void beginPrinting(CliPrinter printer) {}
+
+        abstract void print(CliPrinter printer, ValidationEventFormatter formatter, ValidationEvent event);
+
+        void endPrinting(CliPrinter printer) {}
+
+        private static String formatCsv(String value) {
+            // Replace DQUOTE with DQUOTEDQUOTE, escape newlines, and escape carriage returns.
+            return value.replace("\"", "\"\"").replace("\n", "\\n").replace("\r", "\\r");
+        }
+    }
+
+    private Format format = Format.TEXT;
+
+    @Override
+    public void registerHelp(HelpPrinter printer) {
+        printer.param(VALIDATION_FORMAT, null, "text|csv",
+                      "Specifies the format to write validation events (text or csv). Defaults to text.");
+    }
+
+    @Override
+    public Consumer<String> testParameter(String name) {
+        if (name.equals(VALIDATION_FORMAT)) {
+            return s -> {
+                switch (s) {
+                    case "csv":
+                        format(Format.CSV);
+                        break;
+                    case "text":
+                        format(Format.TEXT);
+                        break;
+                    default:
+                        throw new CliError("Unexpected " + VALIDATION_FORMAT + ": `" + s + "`");
+                }
+            };
+        }
+        return null;
+    }
+
+    void format(Format format) {
+        this.format = format;
+    }
+
+    Format format() {
+        return format;
+    }
+}

smithy-cli/src/test/java/software/amazon/smithy/cli/commands/DiffCommandTest.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.cli.commands;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.junit.jupiter.api.Test;
+import software.amazon.smithy.cli.CliUtils;
+
+public class DiffCommandTest {
+    @Test
+    public void canOutputCsv() throws Exception {
+        Path oldModel = Paths.get(getClass().getResource("diff/old.smithy").toURI());
+        Path newModel = Paths.get(getClass().getResource("diff/new.smithy").toURI());
+        CliUtils.Result result = CliUtils.runSmithy("diff",
+                                                    "--old", oldModel.toString(),
+                                                    "--new", newModel.toString(),
+                                                    "--format", "csv");
+
+        assertThat(result.code(), not(0));
+
+        // Make sure FAILURE is sent to stderr.
+        assertThat(result.stderr(), containsString("FAILURE"));
+        assertThat(result.stdout(), not(containsString("FAILURE")));
+
+        String[] lines = result.stdout().split("(\\r\\n|\\r|\\n)");
+        assertThat(lines.length, is(2));
+        assertThat(lines[0], containsString("severity,id,shape,file,message,hint,suppressionReason"));
+        assertThat(lines[1], containsString("\"ERROR\",\"ChangedShapeType\",\"smithy.example#Hello\""));
+    }
+}

smithy-cli/src/test/java/software/amazon/smithy/cli/commands/ValidateCommandTest.java

@@ -18,7 +18,6 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.not;
 
 import java.net.URISyntaxException;
@@ -216,4 +215,40 @@ public void canHideEventsById() throws Exception {
         assertThat(result.stdout(), not(containsString("EmitDangers")));
         assertThat(result.stdout(), containsString("HttpLabelTrait"));
     }
+
+    @Test
+    public void canOutputCsv() throws Exception {
+        Path validationEventsModel = Paths.get(getClass().getResource("validation-events.smithy").toURI());
+        CliUtils.Result result = CliUtils.runSmithy("validate", "--format", "csv",
+                                                    validationEventsModel.toString());
+
+        assertThat(result.code(), not(0));
+        assertThat(result.stdout(), containsString("suppressionReason"));
+        assertThat(result.stdout(), containsString("EmitWarnings"));
+        assertThat(result.stdout(), containsString("EmitDangers"));
+        assertThat(result.stdout(), containsString("HttpLabelTrait"));
+        assertThat(result.stdout(), not(containsString("FAILURE"))); // stderr
+    }
+
+    @Test
+    public void canOutputText() throws Exception {
+        Path validationEventsModel = Paths.get(getClass().getResource("validation-events.smithy").toURI());
+        CliUtils.Result result = CliUtils.runSmithy("validate", "--format", "text",
+                                                    validationEventsModel.toString());
+
+        assertThat(result.code(), not(0));
+        assertThat(result.stdout(), not(containsString("suppressionReason")));
+        assertThat(result.stdout(), containsString("EmitWarnings"));
+        assertThat(result.stdout(), containsString("EmitDangers"));
+        assertThat(result.stdout(), containsString("HttpLabelTrait"));
+        assertThat(result.stdout(), not(containsString("FAILURE"))); // stderr
+    }
+
+    @Test
+    public void outputFormatMustBeValid() {
+        CliUtils.Result result = CliUtils.runSmithy("validate", "--format", "HELLO");
+
+        assertThat(result.code(), not(0));
+        assertThat(result.stderr(), containsString("Unexpected --format: `HELLO`"));
+    }
 }

smithy-cli/src/test/resources/software/amazon/smithy/cli/commands/diff/new.smithy

@@ -0,0 +1,10 @@
+$version: "2.0"
+
+namespace smithy.example
+
+@deprecated
+string Hello
+
+structure Foo {
+    hello: Hello
+}

smithy-cli/src/test/resources/software/amazon/smithy/cli/commands/diff/old.smithy

@@ -0,0 +1,10 @@
+$version: "2.0"
+
+namespace smithy.example
+
+@deprecated
+integer Hello
+
+structure Foo {
+    hello: Hello
+}