feat: Infer prompt answers (#28)

featherscloud · Jul 9, 2023 · a20827a · a20827a
1 parent 4d052fa
commit a20827a
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Showing 5 changed files with 34 additions and 6 deletions.
diff --git a/packages/pinion/src/declarations.ts b/packages/pinion/src/declarations.ts
@@ -0,0 +1,27 @@
+import type { Question, QuestionCollection } from 'inquirer'
+
+type InferAnswerType<Q extends Question> = Q extends { type: 'input' }
+  ? string
+  : Q extends { type: 'list' }
+  ? string
+  : Q extends { type: 'rawlist' }
+  ? string
+  : Q extends { type: 'number' }
+  ? number
+  : Q extends { type: 'password' }
+  ? string
+  : Q extends { type: 'confirm' }
+  ? boolean
+  : Q extends { type: 'checkbox' }
+  ? string[]
+  : Q extends { type: 'editor' }
+  ? string
+  : unknown
+
+export type InferAnswerTypes<Q extends QuestionCollection> = Q extends ReadonlyArray<
+  Question & { name: string }
+>
+  ? { [K in Q[number] as K['name']]: InferAnswerType<K> }
+  : {
+      [K in keyof Q]: InferAnswerType<Q[K]>
+    }
diff --git a/packages/pinion/src/gpt/operation.ts b/packages/pinion/src/gpt/operation.ts
@@ -72,7 +72,7 @@ export const checkLogin = async <C extends PinionContext>(ctx: C) => {
       user
     }
   } catch (error) {
-    const { loginConfirm } = await prompt<C & { loginConfirm?: boolean }>([
+    const { loginConfirm } = await prompt([
       {
         type: 'confirm',
         name: 'loginConfirm',

diff --git a/packages/pinion/src/index.ts b/packages/pinion/src/index.ts
@@ -3,3 +3,4 @@ export * from './core'
 export * from './ops/index'
 export * from './cli/index'
 export * from './gpt/index'
+export * from './declarations'
diff --git a/packages/pinion/src/ops/prompt.ts b/packages/pinion/src/ops/prompt.ts
@@ -1,6 +1,6 @@
 import { QuestionCollection } from 'inquirer'
-
 import { PinionContext, Callable, getCallable } from '../core'
+import { InferAnswerTypes } from '../declarations'
 import { addTrace } from './helpers'
 
 /**
@@ -10,13 +10,13 @@ import { addTrace } from './helpers'
  * @returns The generator context updated with the prompt results
  */
 export const prompt =
-  <C extends PinionContext, R extends PinionContext = C>(prompts: Callable<QuestionCollection, C>) =>
+  <C extends PinionContext, Q extends QuestionCollection = QuestionCollection>(prompts: Callable<Q, C>) =>
   async <T extends C>(ctx: T) => {
     const answers = await ctx.pinion.prompt(await getCallable(prompts, ctx))
     const result = {
       ...ctx,
       ...answers
-    } as R
+    } as C & InferAnswerTypes<Q>
 
     return addTrace(result, 'prompt', answers)
   }
diff --git a/packages/pinion/test/templates/pinion.ts b/packages/pinion/test/templates/pinion.ts
@@ -36,7 +36,7 @@ export const generate = (ctx: GeneratorArguments) =>
     .then(inject('<!-- Prepended -->', prepend(), toHelloMd))
     .then(inject('<!-- Appended -->', append(), toHelloMd))
     .then(
-      prompt<GeneratorArguments, GeneratorContext>((ctx) => [
+      prompt<GeneratorArguments>((ctx) => [
         {
           type: 'input',
           name: 'name',
@@ -53,7 +53,7 @@ export const generate = (ctx: GeneratorArguments) =>
     )
     .then(copyFiles(fromFile(__dirname), toFile('tmp', 'copy')))
     .then(runGenerators(__dirname))
-    .then((ctx: GeneratorContext) => ({
+    .then((ctx) => ({
       ...ctx,
       finalized: true
     }))