feat: add generateErrors script and update dependencies (MAPCO-8468)

package.json

@@ -49,6 +49,8 @@
   },
   "homepage": "https://github.com/MapColonies/openapi-helpers#readme",
   "dependencies": {
+    "@apidevtools/json-schema-ref-parser": "^14.1.1",
+    "change-case": "^5.4.4",
     "oas-normalize": "^14.1.2",
     "ts-essentials": "^10.1.1",
     "yaml": "^2.8.0"

src/generator/generateErrors.mts

@@ -0,0 +1,129 @@
+import fs from 'node:fs/promises';
+import { parseArgs } from 'node:util';
+import path from 'node:path';
+import { dereference } from '@apidevtools/json-schema-ref-parser';
+import { format, resolveConfig } from 'prettier';
+import * as changeCase from 'change-case';
+import type { OpenAPI3, OperationObject, ResponseObject, SchemaObject } from 'openapi-typescript';
+
+const ARGS_SLICE = 2;
+
+const {
+  values: { format: shouldFormat },
+  positionals,
+} = parseArgs({
+  args: process.argv.slice(ARGS_SLICE),
+  options: {
+    format: { type: 'boolean', alias: 'f' },
+  },
+  allowPositionals: true,
+});
+
+const [openapiPath, destinationPath] = positionals;
+
+if (openapiPath === undefined || destinationPath === undefined) {
+  console.error('Usage: generateErrors <openapiPath> <destinationPath>');
+  process.exit(1);
+}
+
+const openapi = await dereference<OpenAPI3>(openapiPath);
+
+if (openapi.paths === undefined) {
+  console.error('No paths found in the OpenAPI document.');
+  process.exit(1);
+}
+
+const errorCodes = new Set<string>();
+
+function extractCodeFromSchema(schema: SchemaObject): void {
+  // Handle direct code property
+  if (schema.type === 'object' && schema.properties?.code) {
+    const codeProperty = schema.properties.code as SchemaObject;
+
+    // Handle enum values
+    if (codeProperty.enum) {
+      codeProperty.enum.map(String).forEach((code) => {
+        errorCodes.add(code);
+      });
+    }
+  }
+
+  // Handle allOf combinations
+  if (schema.allOf) {
+    for (const subSchema of schema.allOf) {
+      extractCodeFromSchema(subSchema as SchemaObject);
+    }
+  }
+
+  // Handle oneOf combinations
+  if (schema.oneOf) {
+    for (const subSchema of schema.oneOf) {
+      extractCodeFromSchema(subSchema as SchemaObject);
+    }
+  }
+
+  // Handle anyOf combinations
+  if (schema.anyOf) {
+    for (const subSchema of schema.anyOf) {
+      extractCodeFromSchema(subSchema as SchemaObject);
+    }
+  }
+}
+
+function createError(code: string): string {
+  let className = changeCase.pascalCase(code);
+
+  if (!className.endsWith('Error')) {
+    className += 'Error';
+  }
+
+  return `export class ${className} extends Error {
+  public readonly code = '${code}';
+  /**
+   * Creates an instance of ${className}.
+   * @param message - The error message.
+   * @param cause - Optional original error or server response data.
+   */
+  public constructor(message: string, cause?: unknown) {
+    super(message, { cause });
+    Object.setPrototypeOf(this, new.target.prototype);
+  }
+};\n`;
+}
+
+for (const [, methods] of Object.entries(openapi.paths)) {
+  for (const [key, operation] of Object.entries(methods) as [string, OperationObject][]) {
+    if (['servers', 'parameters'].includes(key)) {
+      continue;
+    }
+
+    for (const [statusCode, response] of Object.entries(operation.responses ?? {}) as [string, ResponseObject][]) {
+      if (statusCode.startsWith('2') || statusCode.startsWith('3')) {
+        continue; // Skip successful and redirection responses
+      }
+
+      const schema = response.content?.['application/json']?.schema as SchemaObject | undefined;
+      if (schema) {
+        extractCodeFromSchema(schema);
+      }
+    }
+  }
+}
+
+if (errorCodes.size === 0) {
+  console.warn('No error codes found in the OpenAPI document.');
+  process.exit(0);
+}
+
+let errorFile = errorCodes.values().map(createError).toArray().join('\n');
+
+if (shouldFormat === true) {
+  const prettierOptions = await resolveConfig('./src/index.ts');
+
+  errorFile = await format(errorFile, { ...prettierOptions, parser: 'typescript' });
+}
+
+const directory = path.dirname(destinationPath);
+await fs.mkdir(directory, { recursive: true });
+
+await fs.writeFile(destinationPath, errorFile);

tsconfig.json

@@ -1,5 +1,8 @@
 {
   "extends": "@map-colonies/tsconfig/tsconfig-library",
+  "compilerOptions": {
+    "lib": ["ESNext"]
+  },
   "include": ["src", "tests"],
   "exclude": ["dist", "node_modules"]
 }