feat: add generics to Storage (#1649)

Author: mshima

package-lock.json

@@ -57,7 +57,6 @@
     "chalk": "^5.4.1",
     "debug": "^4.4.1",
     "execa": "^9.5.3",
-    "json-schema": "^0.4.0",
     "latest-version": "^9.0.0",
     "lodash-es": "^4.17.21",
     "mem-fs-editor": "^11.1.4",
@@ -66,12 +65,12 @@
     "semver": "^7.7.2",
     "simple-git": "^3.27.0",
     "sort-keys": "^5.1.0",
-    "text-table": "^0.2.0"
+    "text-table": "^0.2.0",
+    "type-fest": "^4.41.0"
   },
   "devDependencies": {
     "@types/debug": "^4.1.12",
     "@types/ejs": "^3.1.5",
-    "@types/json-schema": "^7.0.15",
     "@types/minimist": "^1.2.5",
     "@types/semver": "^7.7.0",
     "@types/sinon": "^17.0.4",
@@ -88,7 +87,6 @@
     "prettier": "3.5.3",
     "prettier-plugin-packagejson": "2.5.12",
     "sinon": "^20.0.0",
-    "type-fest": "^4.41.0",
     "typescript": "5.8.3",
     "vitest": "^3.1.3",
     "yeoman-assert": "^3.1.1",

package.json

@@ -348,7 +348,7 @@ export class FsMixin {
    */
   _templateData<D extends TemplateData = TemplateData>(this: BaseGenerator, path?: string): D {
     if (path) {
-      return this.config.getPath(path);
+      return this.config.getPath(path) as any as D;
     }
 
     const allConfig: D = this.config.getAll() as D;

src/actions/fs.ts

@@ -23,6 +23,7 @@ import { PackageJsonMixin } from './actions/package-json.js';
 import { SpawnCommandMixin } from './actions/spawn-command.js';
 import { GitMixin } from './actions/user.js';
 import { TasksMixin } from './actions/lifecycle.js';
+import type { PackageJson } from 'type-fest';
 
 type Environment = BaseEnvironment<QueuedAdapter>;
 
@@ -33,10 +34,17 @@ const EMPTY = '@@_YEOMAN_EMPTY_MARKER_@@';
 
 const ENV_VER_WITH_VER_API = '2.9.0';
 
-const packageJson = JSON.parse(readFileSync(pathJoin(_dirname, '../package.json'), 'utf8'));
+const packageJson: PackageJson = JSON.parse(readFileSync(pathJoin(_dirname, '../package.json'), 'utf8'));
 
 // eslint-disable-next-line @typescript-eslint/no-unsafe-declaration-merging
-export class BaseGenerator<O extends BaseOptions = BaseOptions, F extends BaseFeatures = BaseFeatures>
+export class BaseGenerator<
+    ConfigType extends Record<any, any> = Record<any, any>,
+    O extends BaseOptions = BaseOptions,
+    F extends BaseFeatures = BaseFeatures,
+    GeneratorConfigType extends Record<any, any> = Record<any, any>,
+    InstanceConfigType extends Record<any, any> = Record<any, any>,
+    GlobalConfigType extends Record<any, any> = Record<any, any>,
+  >
   extends EventEmitter
   implements Omit<GeneratorApi<O, F>, 'features'>
 {
@@ -68,12 +76,12 @@ export class BaseGenerator<O extends BaseOptions = BaseOptions, F extends BaseFe
   _contextMap?: Map<string, any>;
   _sourceRoot!: string;
 
-  generatorConfig?: Storage;
-  instanceConfig?: Storage;
-  _config?: Storage;
-  _packageJson?: Storage;
+  generatorConfig?: Storage<GeneratorConfigType>;
+  instanceConfig?: Storage<InstanceConfigType>;
+  _config?: Storage<ConfigType>;
+  _packageJson?: Storage<PackageJson>;
 
-  _globalConfig!: Storage;
+  _globalConfig!: Storage<GlobalConfigType>;
 
   // If for some reason environment adds more queues, we should use or own for stability.
   static get queues() {
@@ -92,7 +100,7 @@ export class BaseGenerator<O extends BaseOptions = BaseOptions, F extends BaseFe
 
   _running = false;
   readonly features!: F;
-  readonly yoGeneratorVersion: string = packageJson.version as string;
+  readonly yoGeneratorVersion: string = packageJson.version!;
 
   /**
    * @classdesc The `Generator` class provides the common API shared by all generators.
@@ -630,9 +638,9 @@ export class BaseGenerator<O extends BaseOptions = BaseOptions, F extends BaseFe
   /**
    * Generator config Storage.
    */
-  get config() {
+  get config(): Storage<ConfigType> {
     if (!this._config) {
-      this._config = this._getStorage();
+      this._config = this._getStorage<ConfigType>();
     }
 
     return this._config;
@@ -657,7 +665,7 @@ export class BaseGenerator<O extends BaseOptions = BaseOptions, F extends BaseFe
    *   },
    * });
    */
-  get packageJson(): Storage {
+  get packageJson(): Storage<PackageJson> {
     if (!this._packageJson) {
       this._packageJson = this.createStorage('package.json');
     }
@@ -699,7 +707,11 @@ export class BaseGenerator<O extends BaseOptions = BaseOptions, F extends BaseFe
    * @param storePath  The path of the json file
    * @param options storage options or the storage name
    */
-  createStorage(storePath: string, options?: string | StorageOptions): Storage {
+  createStorage<StoredType extends Record<any, any> = Record<any, any>>(
+    storePath: string,
+    options?: string | StorageOptions,
+  ): Storage<StoredType>;
+  createStorage(storePath: string, options?: string | StorageOptions): Storage<any> {
     if (typeof options === 'string') {
       options = { name: options };
     }
@@ -714,13 +726,16 @@ export class BaseGenerator<O extends BaseOptions = BaseOptions, F extends BaseFe
    * @param options Storage options
    * @return Generator storage
    */
-  _getStorage(rootName: string | StorageOptions = this.rootGeneratorName(), options: StorageOptions = {}) {
+  _getStorage<StoredType extends Record<any, any> = Record<any, any>>(
+    rootName: string | StorageOptions = this.rootGeneratorName(),
+    options: StorageOptions = {},
+  ): Storage<StoredType> {
     if (typeof rootName === 'object') {
       options = rootName;
       rootName = this.rootGeneratorName();
     }
 
-    return this.createStorage('.yo-rc.json', { ...options, name: rootName });
+    return this.createStorage<StoredType>('.yo-rc.json', { ...options, name: rootName });
   }
 
   /**

src/generator.ts

@@ -10,9 +10,10 @@ export type * from './util/storage.js';
 export { default as Storage } from './util/storage.js';
 
 export default class Generator<
+  C extends Record<any, any> = Record<any, any>,
   O extends BaseOptions = BaseOptions,
   F extends BaseFeatures = BaseFeatures,
-> extends BaseGenerator<O, F> {
+> extends BaseGenerator<C, O, F> {
   _simpleGit?: SimpleGit;
 
   constructor(...args: any[]) {

src/index.ts

@@ -5,14 +5,13 @@ import type {
   GeneratorOptions as OptionsApi,
   ProgressOptions,
 } from '@yeoman/types';
-import type { JSONSchema7Type } from 'json-schema';
 import type { PipelineOptions } from 'mem-fs';
 import type { MemFsEditorFile } from 'mem-fs-editor';
+import type { JsonValue } from 'type-fest';
 import type Storage from './util/storage.js';
 import type Generator from './index.js';
 
-export type StorageValue = JSONSchema7Type;
-export type StorageRecord = Record<string, StorageValue>;
+export type StorageValue = JsonValue;
 export type GeneratorPipelineOptions = PipelineOptions<MemFsEditorFile> & ProgressOptions & { pendingFiles?: boolean };
 
 /**

src/types.d.ts

@@ -1,5 +1,4 @@
 import assert from 'node:assert';
-import type { JSONSchema7Object } from 'json-schema';
 import type { PromptAnswers, PromptQuestion } from '../questions.js';
 import type Storage from './storage.js';
 
@@ -173,7 +172,7 @@ export const storeAnswers = (store: Storage, questions: any, answers: PromptAnsw
   assert.ok(typeof answers === 'object', 'answers must be a object');
 
   storeAll = storeAll || false;
-  const promptValues = store.get<JSONSchema7Object>('promptValues') ?? {};
+  const promptValues = store.get('promptValues') ?? {};
 
   questions = [questions].flat();
 

src/util/prompt-suggestion.ts

@@ -1,8 +1,9 @@
 import assert from 'node:assert';
 import { cloneDeep, get, merge, set, defaults as setDefaults } from 'lodash-es';
 import sortKeys from 'sort-keys';
+import type { Get } from 'type-fest';
 import type { MemFsEditor } from 'mem-fs-editor';
-import type { StorageRecord, StorageValue } from '../types.js';
+import type { StorageValue } from '../types.js';
 
 /**
  * Proxy handler for Storage
@@ -71,7 +72,7 @@ export type StorageOptions = {
  *   }
  * }
  */
-class Storage {
+class Storage<StorageRecord extends Record<string, any> = Record<string, any>> {
   path: string;
   name?: string;
   fs: MemFsEditor;
@@ -196,7 +197,7 @@ class Storage {
       if (this.lodashPath) {
         set(fullStore, this.name, value);
       } else {
-        fullStore[this.name] = value;
+        (fullStore as any)[this.name] = value;
       }
     } else {
       fullStore = value;
@@ -217,17 +218,17 @@ class Storage {
    * @param key  The key under which the value is stored.
    * @return The stored value. Any JSON valid type could be returned
    */
-  get<T extends StorageValue = StorageValue>(key: string): T {
-    return this._store[key] as T;
+  get<const Key extends keyof StorageRecord>(key: Key): StorageRecord[Key] {
+    return this._store[key];
   }
 
   /**
    * Get a stored value from a lodash path
    * @param path  The path under which the value is stored.
    * @return The stored value. Any JSON valid type could be returned
    */
-  getPath<T extends StorageValue = StorageValue>(path: string): T {
-    return get(this._store, path) as T;
+  getPath<const KeyPath extends string>(path: KeyPath): Get<StorageValue, KeyPath> {
+    return get(this._store, path);
   }
 
   /**
@@ -244,21 +245,26 @@ class Storage {
    * @param val  Any valid JSON type value (String, Number, Array, Object).
    * @return val  Whatever was passed in as val.
    */
-  set<V = StorageValue>(value: V): V;
-  set<V = StorageValue>(key: string | number, value?: V): V | undefined;
-  set<V = StorageValue>(key: string | number | V, value?: V): V | undefined {
+  set(value: Partial<StorageRecord>): StorageRecord;
+  set<const Key extends keyof StorageRecord, const Value extends StorageRecord[Key]>(
+    key: Key,
+    value?: Value,
+  ): Value | undefined;
+  set(key: string | number | Partial<StorageRecord>, value?: StorageValue): StorageRecord | StorageValue | undefined {
     const store = this._store;
+    let ret: StorageValue | StorageValue | undefined;
 
     if (typeof key === 'object') {
-      value = Object.assign(store, key);
+      ret = Object.assign(store, key);
     } else if (typeof key === 'string' || typeof key === 'number') {
-      store[key] = value as any;
+      (store as any)[key] = value;
+      ret = value;
     } else {
       throw new TypeError(`key not supported ${typeof key}`);
     }
 
     this._persist(store);
-    return value;
+    return ret;
   }
 
   /**
@@ -267,7 +273,7 @@ class Storage {
    * @param val  Any valid JSON type value (String, Number, Array, Object).
    * @return val  Whatever was passed in as val.
    */
-  setPath(path: string | number, value: StorageValue) {
+  setPath<const KeyPath extends string>(path: KeyPath, value: Get<StorageValue, KeyPath>): Get<StorageValue, KeyPath> {
     assert(typeof value !== 'function', "Storage value can't be a function");
 
     const store = this._store;
@@ -280,7 +286,7 @@ class Storage {
    * Delete a key from the store and schedule a save.
    * @param key  The key under which the value is stored.
    */
-  delete(key: string) {
+  delete(key: keyof StorageRecord): void {
     const store = this._store;
 
     delete store[key];
@@ -293,7 +299,7 @@ class Storage {
    * @param defaults  Key-value object to store.
    * @return val  Returns the merged options.
    */
-  defaults(defaults: StorageRecord): StorageRecord {
+  defaults(defaults: Partial<StorageRecord>): StorageRecord {
     assert(typeof defaults === 'object', 'Storage `defaults` method only accept objects');
     const store = setDefaults({}, this._store, defaults);
     this._persist(store);
@@ -304,7 +310,7 @@ class Storage {
    * @param defaults  Key-value object to store.
    * @return val  Returns the merged object.
    */
-  merge(source: StorageRecord) {
+  merge(source: Partial<StorageRecord>): StorageRecord {
     assert(typeof source === 'object', 'Storage `merge` method only accept objects');
     const value = merge({}, this._store, source);
     this._persist(value);
@@ -317,9 +323,9 @@ class Storage {
    *                         Some paths need to be escaped. Eg: ["dotted.path"]
    * @return Returns a new Storage.
    */
-  createStorage(path: string): Storage {
+  createStorage<const KeyPath extends string>(path: KeyPath): Storage<Get<StorageRecord, KeyPath>> {
     const childName = this.name ? `${this.name}.${path}` : path;
-    return new Storage(childName, this.fs, this.path, { lodashPath: true });
+    return new Storage<Get<StorageRecord, KeyPath>>(childName, this.fs, this.path, { lodashPath: true });
   }
 
   /**