feat: implemented logic to output diagnostics log by adding additional output flag to validate cli command. (#1563)

Co-authored-by: Souvik De <souvikde.ns@gmail.com>

Author: SahilDahekar

src/core/parser.ts

@@ -12,11 +12,29 @@ import { red, yellow, green, cyan } from 'chalk';
 import type { Diagnostic } from '@asyncapi/parser/cjs';
 import type Command from './base';
 import type { Specification } from './models/SpecificationFile';
+import { promises } from 'fs';
+import path from 'path';
+
+type DiagnosticsFormat = 'stylish' | 'json' | 'junit' | 'html' | 'text' | 'teamcity' | 'pretty';
 
 export type SeverityKind = 'error' | 'warn' | 'info' | 'hint';
 
 export { convertToOldAPI };
 
+const { writeFile } = promises;
+
+const formatExtensions: Record<DiagnosticsFormat, string> = {
+  stylish: '.txt',
+  json: '.json',
+  junit: '.xml',
+  html: '.html',
+  text: '.txt',
+  teamcity: '.txt',
+  pretty: '.txt',
+};
+
+const validFormats = ['stylish', 'json', 'junit', 'html', 'text', 'teamcity', 'pretty'];
+
 const parser = new Parser({
   __unstable: {
     resolver: {
@@ -56,13 +74,18 @@ export function validationFlags({ logDiagnostics = true }: ValidationFlagsOption
       options: ['error', 'warn', 'info', 'hint'] as const,
       default: 'error',
     })(),
+    output: Flags.string({
+      description: 'The output file name. Omitting this flag the result will be printed in the console.',
+      char: 'o' 
+    })
   };
 }
 
 export interface ValidateOptions {
   'log-diagnostics'?: boolean;
   'diagnostics-format'?: `${OutputFormat}`;
   'fail-severity'?: SeverityKind;
+  'output'?: string;
 }
 
 export async function validate(command: Command, specFile: Specification, options: ValidateOptions = {}) {
@@ -76,30 +99,56 @@ export async function parse(command: Command, specFile: Specification, options:
   return { document, diagnostics, status };
 }
 
-function logDiagnostics(diagnostics: Diagnostic[], command: Command, specFile: Specification, options: ValidateOptions = {}): 'valid' | 'invalid' {
+function logDiagnostics(
+  diagnostics: Diagnostic[],
+  command: Command,
+  specFile: Specification,
+  options: ValidateOptions = {}
+): 'valid' | 'invalid' {
   const logDiagnostics = options['log-diagnostics'];
   const failSeverity = options['fail-severity'] ?? 'error';
   const diagnosticsFormat = options['diagnostics-format'] ?? 'stylish';
-
   const sourceString = specFile.toSourceString();
-  if (diagnostics.length) {
-    if (hasFailSeverity(diagnostics, failSeverity)) {
-      if (logDiagnostics) {
-        command.logToStderr(`\n${sourceString} and/or referenced documents have governance issues.`);
-        command.logToStderr(formatOutput(diagnostics, diagnosticsFormat, failSeverity));
-      }
-      return ValidationStatus.INVALID;
-    }
 
-    if (logDiagnostics) {
-      command.log(`\n${sourceString} is valid but has (itself and/or referenced documents) governance issues.`);
-      command.log(formatOutput(diagnostics, diagnosticsFormat, failSeverity));
-    }
-  } else if (logDiagnostics) {
+  const hasIssues = diagnostics.length > 0;
+  const isFailSeverity = hasIssues && hasFailSeverity(diagnostics, failSeverity);
+
+  if (logDiagnostics) {
+    logGovernanceMessage(command, sourceString, hasIssues, isFailSeverity);
+    outputDiagnostics(command, diagnostics, diagnosticsFormat, failSeverity, options);
+  }
+
+  return isFailSeverity ? ValidationStatus.INVALID : ValidationStatus.VALID;
+}
+
+function logGovernanceMessage(
+  command: Command,
+  sourceString: string,
+  hasIssues: boolean,
+  isFailSeverity: boolean
+) {
+  if (!hasIssues) {
     command.log(`\n${sourceString} is valid! ${sourceString} and referenced documents don't have governance issues.`);
+  } else if (isFailSeverity) {
+    command.logToStderr(`\n${sourceString} and/or referenced documents have governance issues.`);
+  } else {
+    command.log(`\n${sourceString} is valid but has (itself and/or referenced documents) governance issues.`);
   }
+}
 
-  return ValidationStatus.VALID;
+function outputDiagnostics(
+  command: Command,
+  diagnostics: Diagnostic[],
+  diagnosticsFormat: DiagnosticsFormat,
+  failSeverity: SeverityKind,
+  options: ValidateOptions
+) {
+  const diagnosticsOutput = formatOutput(diagnostics, diagnosticsFormat, failSeverity);
+  if (options.output) {
+    writeValidationDiagnostic(options.output, command, diagnosticsFormat, diagnosticsOutput);
+  } else {
+    command.log(diagnosticsOutput);
+  }
 }
 
 export function formatOutput(diagnostics: Diagnostic[], format: `${OutputFormat}`, failSeverity: SeverityKind) {
@@ -145,3 +194,22 @@ function hasFailSeverity(diagnostics: Diagnostic[], failSeverity: SeverityKind)
   const diagnosticSeverity = getDiagnosticSeverity(failSeverity);
   return diagnostics.some(diagnostic => diagnostic.severity <= diagnosticSeverity);
 }
+
+async function writeValidationDiagnostic(outputPath: string, command: Command, format: DiagnosticsFormat, formatOutput: string) {
+  if (!validFormats.includes(format)) {
+    command.logToStderr(`Invalid diagnostics format: "${format}"`);
+    return;
+  }
+
+  const expectedExtension = formatExtensions[format as keyof typeof formatExtensions];
+  const actualExtension = path.extname(outputPath);
+
+  // Validate file extension against diagnostics format
+  if (expectedExtension && (actualExtension !== expectedExtension)) {
+    command.logToStderr(`Invalid file extension for format "${format}". Expected extension: "${expectedExtension}"`);
+  } else {
+    await writeFile(path.resolve(process.cwd(), outputPath), formatOutput, {
+      encoding: 'utf-8',
+    }).catch(err => console.log(err));
+  }
+}