feat: generate type definitions from the json schema

Author: k-yle

eslint.config.mjs

@@ -30,7 +30,6 @@ export default [
       'indent': ['off', 4],
       'keyword-spacing': 'error',
       'linebreak-style': ['error', 'unix'],
-      'no-await-in-loop': 'error',
       'no-caller': 'error',
       'no-catch-shadow': 'error',
       'no-console': 'warn',

lib/build.js

@@ -3,10 +3,13 @@ import fs from 'fs';
 import { globSync } from 'glob';
 import jsonschema from 'jsonschema';
 import path from 'path';
+import { fileURLToPath } from 'url';
 import shell from 'shelljs';
 import YAML from 'js-yaml';
 import marky from 'marky';
 import { createRequire } from 'module';
+import { compileFromFile } from 'json-schema-to-typescript';
+import { toSafeString } from 'json-schema-to-typescript/dist/src/utils.js';
 
 import fetchTranslations from './translations.js';
 
@@ -187,7 +190,8 @@ function processData(options, type) {
     minifyJSON(distDir + '/preset_defaults.json', distDir + '/preset_defaults.min.json'),
     minifyJSON(distDir + '/deprecated.json', distDir + '/deprecated.min.json'),
     minifyJSON(distDir + '/discarded.json', distDir + '/discarded.min.json'),
-    minifyJSON(distDir + '/translations/' + sourceLocale + '.json', distDir + '/translations/' + sourceLocale + '.min.json')
+    minifyJSON(distDir + '/translations/' + sourceLocale + '.json', distDir + '/translations/' + sourceLocale + '.min.json'),
+    generateTypeDefs(distDir),
   ];
 
   if (doFetchTranslations) {
@@ -693,6 +697,68 @@ function generateIconsList(presets, fields, categories) {
   return Object.keys(icons).sort();
 }
 
+/** @param {string} distDir */
+async function generateTypeDefs(distDir) {
+  const __dirname = path.dirname(fileURLToPath(import.meta.url));
+  const inputFolder = path.join(__dirname, '../schemas');
+
+  /**
+   * Some generated files use plural names because they
+   * export an object, e.g. `Fields = Record<string, Field>`
+   */
+  const KEY_MAP = {
+    field: 'fields',
+    preset: 'presets',
+    preset_category: 'preset_categories',
+  };
+  const fileNames = await fs.promises.readdir(inputFolder);
+
+  for (const fileName of fileNames) {
+    const key = fileName.replace('.json', '');
+    const pluralKey = KEY_MAP[key];
+
+    let base = `
+      declare const json: ${toSafeString(pluralKey || key)};
+      export default json;
+    `;
+
+    if (pluralKey) {
+      base += `
+        export type ${toSafeString(pluralKey)} = {
+          [id: string]: ${toSafeString(key)}
+        };
+      `;
+    }
+
+    const tsFile = await compileFromFile(path.join(inputFolder, fileName), {
+      additionalProperties: false,
+      bannerComment: base,
+
+      // ensure that the default export uses a consistent name
+      customName: (schema) =>
+        schema.$schema && schema.$id ? path.parse(schema.$id).name : undefined,
+    });
+
+    await fs.promises.writeFile(
+      path.join(distDir, `${pluralKey || key}.d.json.ts`),
+      tsFile,
+    );
+  }
+
+  // finally, create the index file which re-exports everything
+  // as named types.
+  const indexFile = fileNames
+    .map((fileName) => {
+      const key = fileName.replace('.json', '');
+      return `export type * from './${KEY_MAP[key] || key}.d.json.ts';`;
+    })
+    .join('\n');
+
+  await fs.promises.writeFile(
+    path.join(distDir, 'index.d.ts'),
+    indexFile + '\n',
+  );
+}
 
 function validateCategoryPresets(categories, presets) {
   Object.keys(categories).forEach(id => {