inquirerer defaultFrom feature

Author: pyramation

packages/inquirerer/examples/defaultFrom-example.ts

@@ -0,0 +1,104 @@
+import { Inquirerer, registerDefaultResolver } from '../src';
+
+/**
+ * Example demonstrating the new defaultFrom feature
+ *
+ * This feature allows questions to automatically populate defaults from:
+ * - Git configuration (git.user.name, git.user.email)
+ * - Date/time values (date.year, date.iso, date.now)
+ * - Custom resolvers you register
+ */
+
+async function basicExample() {
+    console.log('=== Basic Example: Git and Date Resolvers ===\n');
+
+    const questions = [
+        {
+            name: 'authorName',
+            type: 'text' as const,
+            message: 'Author name?',
+            defaultFrom: 'git.user.name'  // Auto-fills from git config
+        },
+        {
+            name: 'authorEmail',
+            type: 'text' as const,
+            message: 'Author email?',
+            defaultFrom: 'git.user.email'  // Auto-fills from git config
+        },
+        {
+            name: 'year',
+            type: 'text' as const,
+            message: 'Copyright year?',
+            defaultFrom: 'date.year'  // Auto-fills current year
+        }
+    ];
+
+    const prompter = new Inquirerer();
+    const answers = await prompter.prompt({}, questions);
+
+    console.log('\nAnswers:', answers);
+    prompter.close();
+}
+
+async function customResolverExample() {
+    console.log('\n=== Custom Resolver Example ===\n');
+
+    // Register custom resolvers
+    registerDefaultResolver('package.name', async () => {
+        // In a real app, you'd read from package.json
+        return 'my-awesome-package';
+    });
+
+    registerDefaultResolver('cwd.name', () => {
+        return process.cwd().split('/').pop();
+    });
+
+    const questions = [
+        {
+            name: 'pkgName',
+            type: 'text' as const,
+            message: 'Package name?',
+            defaultFrom: 'package.name'  // Uses custom resolver
+        },
+        {
+            name: 'dirName',
+            type: 'text' as const,
+            message: 'Directory name?',
+            defaultFrom: 'cwd.name'  // Uses custom resolver
+        }
+    ];
+
+    const prompter = new Inquirerer();
+    const answers = await prompter.prompt({}, questions);
+
+    console.log('\nAnswers:', answers);
+    prompter.close();
+}
+
+async function allAvailableResolvers() {
+    console.log('\n=== All Built-in Resolvers ===\n');
+
+    const builtInResolvers = [
+        'git.user.name',
+        'git.user.email',
+        'date.year',
+        'date.month',
+        'date.day',
+        'date.now',
+        'date.iso',
+        'date.timestamp'
+    ];
+
+    console.log('Built-in resolvers available:');
+    builtInResolvers.forEach(resolver => {
+        console.log(`  - ${resolver}`);
+    });
+}
+
+// Run examples
+(async () => {
+    await allAvailableResolvers();
+    // Uncomment to run interactive examples:
+    // await basicExample();
+    // await customResolverExample();
+})();

packages/inquirerer/src/index.ts

@@ -1,3 +1,4 @@
 export * from './commander';
 export * from './prompt';
-export * from './question';
+export * from './question';
+export * from './resolvers';

packages/inquirerer/src/prompt.ts

@@ -4,6 +4,7 @@ import { Readable, Writable } from 'stream';
 
 import { KEY_CODES, TerminalKeypress } from './keypress';
 import { AutocompleteQuestion, CheckboxQuestion, ConfirmQuestion, ListQuestion, NumberQuestion, OptionValue, Question, TextQuestion, Validation, Value } from './question';
+import { DefaultResolverRegistry, globalResolverRegistry } from './resolvers';
 // import { writeFileSync } from 'fs';
 
 // const debuglog = (obj: any) => {
@@ -250,6 +251,7 @@ export interface InquirererOptions {
   useDefaults?: boolean;
   globalMaxLines?: number;
   mutateArgs?: boolean;
+  resolverRegistry?: DefaultResolverRegistry;
 
 }
 export class Inquirerer {
@@ -261,6 +263,7 @@ export class Inquirerer {
   private useDefaults: boolean;
   private globalMaxLines: number;
   private mutateArgs: boolean;
+  private resolverRegistry: DefaultResolverRegistry;
 
   private handledKeys: Set<string> = new Set();
 
@@ -273,7 +276,8 @@ export class Inquirerer {
       output = process.stdout,
       useDefaults = false,
       globalMaxLines = 10,
-      mutateArgs = true
+      mutateArgs = true,
+      resolverRegistry = globalResolverRegistry
     } = options ?? {}
 
     this.useDefaults = useDefaults;
@@ -282,6 +286,7 @@ export class Inquirerer {
     this.mutateArgs = mutateArgs;
     this.input = input;
     this.globalMaxLines = globalMaxLines;
+    this.resolverRegistry = resolverRegistry;
 
     if (!noTty) {
       this.rl = readline.createInterface({
@@ -461,6 +466,9 @@ export class Inquirerer {
     const shouldMutate = options?.mutateArgs !== undefined ? options.mutateArgs : this.mutateArgs;
     let obj: any = shouldMutate ? argv : { ...argv };
 
+    // Resolve dynamic defaults before processing questions
+    await this.resolveDynamicDefaults(questions);
+
     // first loop through the question, and set any overrides in case other questions use objs for validation
     this.applyOverrides(argv, obj, questions);
 
@@ -543,6 +551,43 @@ export class Inquirerer {
     return questions.some(question => question.required && this.isEmptyAnswer(argv[question.name]));
   }
 
+  /**
+   * Resolves the default value for a question using the resolver system.
+   * Priority: defaultFrom > default > undefined
+   */
+  private async resolveQuestionDefault(question: Question): Promise<any> {
+    // Try to resolve from defaultFrom first
+    if ('defaultFrom' in question && question.defaultFrom) {
+      const resolved = await this.resolverRegistry.resolve(question.defaultFrom);
+      if (resolved !== undefined) {
+        return resolved;
+      }
+    }
+
+    // Fallback to static default
+    if ('default' in question) {
+      return question.default;
+    }
+
+    return undefined;
+  }
+
+  /**
+   * Resolves dynamic defaults for all questions that have defaultFrom specified.
+   * Updates the question.default property with the resolved value.
+   */
+  private async resolveDynamicDefaults(questions: Question[]): Promise<void> {
+    for (const question of questions) {
+      if ('defaultFrom' in question && question.defaultFrom) {
+        const resolved = await this.resolveQuestionDefault(question);
+        if (resolved !== undefined) {
+          // Update question.default with resolved value
+          (question as any).default = resolved;
+        }
+      }
+    }
+  }
+
   private applyDefaultValues(questions: Question[], obj: any): void {
     questions.forEach(question => {
       if ('default' in question) {

packages/inquirerer/src/question/types.ts

@@ -18,6 +18,7 @@ export interface BaseQuestion {
     name: string;
     type: string;
     default?: any;
+    defaultFrom?: string;
     useDefault?: boolean;
     required?: boolean;
     message?: string;

packages/inquirerer/src/resolvers/date.ts

@@ -0,0 +1,13 @@
+import type { ResolverRegistry } from './types';
+
+/**
+ * Built-in date/time resolvers.
+ */
+export const dateResolvers: ResolverRegistry = {
+    'date.year': () => new Date().getFullYear().toString(),
+    'date.month': () => (new Date().getMonth() + 1).toString().padStart(2, '0'),
+    'date.day': () => new Date().getDate().toString().padStart(2, '0'),
+    'date.now': () => new Date().toISOString(),
+    'date.iso': () => new Date().toISOString().split('T')[0], // YYYY-MM-DD
+    'date.timestamp': () => Date.now().toString(),
+};

packages/inquirerer/src/resolvers/git.ts

@@ -0,0 +1,28 @@
+import { execSync } from 'child_process';
+import type { ResolverRegistry } from './types';
+
+/**
+ * Retrieves a git config value.
+ * @param key The git config key (e.g., 'user.name', 'user.email')
+ * @returns The config value as a string, or undefined if not found or error occurs
+ */
+export function getGitConfig(key: string): string | undefined {
+    try {
+        const result = execSync(`git config --global ${key}`, {
+            encoding: 'utf8',
+            stdio: ['pipe', 'pipe', 'ignore'] // Suppress stderr
+        });
+        const trimmed = result.trim();
+        return trimmed || undefined; // Treat empty string as undefined
+    } catch {
+        return undefined;
+    }
+}
+
+/**
+ * Built-in git configuration resolvers.
+ */
+export const gitResolvers: ResolverRegistry = {
+    'git.user.name': () => getGitConfig('user.name'),
+    'git.user.email': () => getGitConfig('user.email'),
+};

packages/inquirerer/src/resolvers/index.ts

@@ -0,0 +1,113 @@
+import { gitResolvers } from './git';
+import { dateResolvers } from './date';
+import type { DefaultResolver, ResolverRegistry } from './types';
+
+/**
+ * A registry for managing default value resolvers.
+ * Allows registration of custom resolvers and provides resolution logic.
+ */
+export class DefaultResolverRegistry {
+    private resolvers: ResolverRegistry;
+
+    constructor(initialResolvers: ResolverRegistry = {}) {
+        this.resolvers = { ...initialResolvers };
+    }
+
+    /**
+     * Register a custom resolver.
+     * @param key The resolver key (e.g., 'git.user.name')
+     * @param resolver The resolver function
+     */
+    register(key: string, resolver: DefaultResolver): void {
+        this.resolvers[key] = resolver;
+    }
+
+    /**
+     * Unregister a resolver.
+     * @param key The resolver key to remove
+     */
+    unregister(key: string): void {
+        delete this.resolvers[key];
+    }
+
+    /**
+     * Resolve a key to its value.
+     * Returns undefined if the resolver doesn't exist or if it throws an error.
+     * @param key The resolver key
+     * @returns The resolved value or undefined
+     */
+    async resolve(key: string): Promise<any> {
+        const resolver = this.resolvers[key];
+        if (!resolver) {
+            return undefined;
+        }
+
+        try {
+            const result = await Promise.resolve(resolver());
+            // Treat empty strings as undefined
+            return result === '' ? undefined : result;
+        } catch (error) {
+            // Silent failure - log only in debug mode
+            if (process.env.DEBUG === 'inquirerer') {
+                console.error(`[inquirerer] Resolver '${key}' failed:`, error);
+            }
+            return undefined;
+        }
+    }
+
+    /**
+     * Check if a resolver exists for the given key.
+     * @param key The resolver key
+     * @returns True if the resolver exists
+     */
+    has(key: string): boolean {
+        return key in this.resolvers;
+    }
+
+    /**
+     * Get all registered resolver keys.
+     * @returns Array of resolver keys
+     */
+    keys(): string[] {
+        return Object.keys(this.resolvers);
+    }
+
+    /**
+     * Create a copy of this registry with all current resolvers.
+     * @returns A new DefaultResolverRegistry instance
+     */
+    clone(): DefaultResolverRegistry {
+        return new DefaultResolverRegistry({ ...this.resolvers });
+    }
+}
+
+/**
+ * Global resolver registry instance with built-in resolvers.
+ * This is the default registry used by Inquirerer unless a custom one is provided.
+ */
+export const globalResolverRegistry = new DefaultResolverRegistry({
+    ...gitResolvers,
+    ...dateResolvers,
+});
+
+/**
+ * Convenience function to register a resolver on the global registry.
+ * @param key The resolver key
+ * @param resolver The resolver function
+ */
+export function registerDefaultResolver(key: string, resolver: DefaultResolver): void {
+    globalResolverRegistry.register(key, resolver);
+}
+
+/**
+ * Convenience function to resolve a key using the global registry.
+ * @param key The resolver key
+ * @returns The resolved value or undefined
+ */
+export function resolveDefault(key: string): Promise<any> {
+    return globalResolverRegistry.resolve(key);
+}
+
+// Re-export types and utilities
+export type { DefaultResolver, ResolverRegistry } from './types';
+export { getGitConfig } from './git';

packages/inquirerer/src/resolvers/types.ts

@@ -0,0 +1,13 @@
+/**
+ * A function that resolves a default value dynamically.
+ * Can be synchronous or asynchronous.
+ */
+export type DefaultResolver = () => Promise<any> | any;
+
+/**
+ * A registry of resolver functions, keyed by their resolver name.
+ * Example: { 'git.user.name': () => getGitConfig('user.name') }
+ */
+export interface ResolverRegistry {
+    [key: string]: DefaultResolver;
+}