From 0858fde9906e968778ae24db6e454ee542ff7ddb Mon Sep 17 00:00:00 2001
From: Jason Kuhrt <jasonkuhrt@me.com>
Date: Wed, 18 Dec 2024 18:28:12 -0500
Subject: [PATCH] feat(generator): ability to control import extension (#1284)

---
 src/generator/config/config.test.ts      | 22 +++++++
 src/generator/config/config.ts           |  5 +-
 src/generator/config/configInit.ts       | 74 ++++++++++++++++++------
 src/generator/config/defaults.ts         |  4 +-
 src/generator/generator/generate.test.ts | 28 ++++++++-
 src/generator/helpers/moduleGenerator.ts | 12 +++-
 6 files changed, 123 insertions(+), 22 deletions(-)

diff --git a/src/generator/config/config.test.ts b/src/generator/config/config.test.ts
index dc9ed8c9b..a39e85b4d 100644
--- a/src/generator/config/config.test.ts
+++ b/src/generator/config/config.test.ts
@@ -1,6 +1,28 @@
 import { expect } from 'vitest'
+import { describe } from 'vitest'
 import { test } from '../../../tests/_/helpers.js'
 import { createConfig } from './config.js'
+import type { ConfigInitSchemaSdl } from './configInit.js'
+
+const schema: ConfigInitSchemaSdl = {
+  type: `sdl`,
+  sdl: `type Query { ok: Boolean }`,
+}
+
+describe(`import format`, () => {
+  test(`defaults to jsExtension`, async () => {
+    const config = await createConfig({ schema })
+    expect(config.importFormat).toEqual(`jsExtension`)
+  })
+  test(`noExtension`, async () => {
+    const customPathFile = `./tests/_/fixtures/custom.graphql`
+    const config = await createConfig({
+      schema: { type: `sdlFile`, dirOrFilePath: customPathFile },
+      importFormat: `noExtension`,
+    })
+    expect(config.importFormat).toEqual(`noExtension`)
+  })
+})
 
 test(`can load schema from custom path`, async () => {
   const customPathFile = `./tests/_/fixtures/custom.graphql`
diff --git a/src/generator/config/config.ts b/src/generator/config/config.ts
index 5c677c42b..260b94aec 100644
--- a/src/generator/config/config.ts
+++ b/src/generator/config/config.ts
@@ -11,11 +11,12 @@ import type { Extension } from '../extension/types.js'
 import {
   type ConfigInit,
   type ConfigInitLibraryPaths,
+  type InputImportFormat,
   type InputLint,
   type InputOutputCase,
   libraryPathKeys,
 } from './configInit.js'
-import { defaultLibraryPaths, defaultNamespace, defaultOutputCase } from './defaults.js'
+import { defaultImportFormat, defaultLibraryPaths, defaultNamespace, defaultOutputCase } from './defaults.js'
 import { defaultName } from './defaults.js'
 
 export interface Config {
@@ -43,6 +44,7 @@ export interface Config {
   }
   formatter: Formatter
   extensions: Extension[]
+  importFormat: InputImportFormat
   paths: {
     project: {
       inputs: {
@@ -201,6 +203,7 @@ To suppress this warning disable formatting in one of the following ways:
   return {
     fs,
     name,
+    importFormat: configInit.importFormat ?? defaultImportFormat,
     nameNamespace,
     extensions: configInit.extensions ?? [],
     outputCase,
diff --git a/src/generator/config/configInit.ts b/src/generator/config/configInit.ts
index def4dfe66..35cd6249c 100644
--- a/src/generator/config/configInit.ts
+++ b/src/generator/config/configInit.ts
@@ -20,6 +20,39 @@ export const OutputCase = {
 } as const
 export type InputOutputCase = keyof typeof OutputCase
 
+export const ImportFormat = {
+  jsExtension: `jsExtension`,
+  tsExtension: `tsExtension`,
+  noExtension: `noExtension`,
+} as const
+export type InputImportFormat = keyof typeof ImportFormat
+
+export interface ConfigInitSchemaSdl {
+  type: `sdl`
+  sdl: string
+}
+export interface ConfigInitSchemaInstance {
+  type: `instance`
+  instance: Grafaid.Schema.Schema
+}
+export interface ConfigInitSchemaSdlFile {
+  type: `sdlFile`
+  /**
+   * Defaults to the source directory if set, otherwise the current working directory.
+   */
+  dirOrFilePath?: string
+}
+export interface ConfigInitSchemaUrl {
+  type: `url`
+  url: URL
+  options?: InputIntrospectionOptions
+}
+
+export type ConfigInitSchema =
+  | ConfigInitSchemaSdl
+  | ConfigInitSchemaInstance
+  | ConfigInitSchemaSdlFile
+  | ConfigInitSchemaUrl
 export interface ConfigInit {
   /**
    * File system API to use.
@@ -66,25 +99,13 @@ export interface ConfigInit {
    */
   currentWorkingDirectory?: string
   /**
-   * The schema to use for generation. Can be an existing SDL file on disk, a schema instance already in memory, or an endpoint that will be introspected.
+   * The schema to use for generation. Can be one of:
+   *
+   * 1. An existing SDL file on disk,
+   * 2. A schema instance already in memory,
+   * 3. An endpoint that will be introspected.
    */
-  schema: {
-    type: 'sdl'
-    sdl: string
-  } | {
-    type: 'instance'
-    instance: Grafaid.Schema.Schema
-  } | {
-    type: 'sdlFile'
-    /**
-     * Defaults to the source directory if set, otherwise the current working directory.
-     */
-    dirOrFilePath?: string
-  } | {
-    type: 'url'
-    url: URL
-    options?: InputIntrospectionOptions
-  }
+  schema: ConfigInitSchema
   /**
    * If the schema comes from a non-sdl-file source like a GraphQL endpoint URL, should a derived SDL file be written to disk?
    *
@@ -136,6 +157,23 @@ export interface ConfigInit {
    * If not set, Graffle will look for a file called `scalars.ts` in the project directory.
    */
   scalars?: string
+  /**
+   * How should import identifiers be generated? Can be one of:
+   *
+   * 1. `jsExtension` e.g. `import ... from './bar.js'`
+   * 2. `tsExtension` e.g. `import ... from './bar.ts'`
+   * 3. `noExtension` e.g. `import ... from './bar'`
+   *
+   * @defaultValue `jsExtension`
+   *
+   * @remarks
+   *
+   * A user request for this option can be found at https://github.com/graffle-js/graffle/issues/1282.
+   *
+   * There is a planned feature to have a default be dynamic according to the state of your project's tsconfig.json.
+   * See https://github.com/graffle-js/graffle/issues/1283.
+   */
+  importFormat?: InputImportFormat
   /**
    * Override import paths to graffle package within the generated code.
    * Used by Graffle test suite to have generated clients point to source
diff --git a/src/generator/config/defaults.ts b/src/generator/config/defaults.ts
index 11223bd05..25af56e67 100644
--- a/src/generator/config/defaults.ts
+++ b/src/generator/config/defaults.ts
@@ -1,4 +1,4 @@
-import type { ConfigInitLibraryPaths, InputOutputCase } from './configInit.js'
+import type { ConfigInitLibraryPaths, InputImportFormat, InputOutputCase } from './configInit.js'
 
 export const defaultNamespace = `Graffle`
 
@@ -13,3 +13,5 @@ export const defaultLibraryPaths = {
 } satisfies ConfigInitLibraryPaths
 
 export const defaultOutputCase: InputOutputCase = `kebab`
+
+export const defaultImportFormat: InputImportFormat = `jsExtension`
diff --git a/src/generator/generator/generate.test.ts b/src/generator/generator/generate.test.ts
index b5779b49e..ee29d1cf8 100644
--- a/src/generator/generator/generate.test.ts
+++ b/src/generator/generator/generate.test.ts
@@ -2,9 +2,35 @@ import { globby } from 'globby'
 import * as Memfs from 'memfs'
 import { readFile } from 'node:fs/promises'
 import * as Path from 'node:path'
-import { expect, test } from 'vitest'
+import { describe, expect, test } from 'vitest'
+import type { ConfigInitSchemaSdl } from '../_.js'
 import { generate } from './generate.js'
 
+const schema: ConfigInitSchemaSdl = {
+  type: `sdl`,
+  sdl: `type Query { ok: Boolean }`,
+}
+
+describe(`importFormat`, () => {
+  test(`default is jsExtension`, async () => {
+    await generate({
+      fs: Memfs.fs.promises as any,
+      schema,
+    })
+    const SchemaTs = Memfs.fs.readFileSync(`./graffle/modules/schema.ts`, `utf8`)
+    expect(SchemaTs).toMatch(/import.*".\/data.js"/)
+  })
+  test(`noExtension`, async () => {
+    await generate({
+      fs: Memfs.fs.promises as any,
+      schema,
+      importFormat: `noExtension`,
+    })
+    const SchemaTs = Memfs.fs.readFileSync(`./graffle/modules/schema.ts`, `utf8`)
+    expect(SchemaTs).toMatch(/import.*".\/data"/)
+  })
+})
+
 test(`kitchen-sink generated modules`, async () => {
   const basePath = `./tests/_/schemas/kitchen-sink/graffle`
   const filePaths = await globby(`${basePath}/**/*.ts`)
diff --git a/src/generator/helpers/moduleGenerator.ts b/src/generator/helpers/moduleGenerator.ts
index fc8a1129f..86c38a7e1 100644
--- a/src/generator/helpers/moduleGenerator.ts
+++ b/src/generator/helpers/moduleGenerator.ts
@@ -1,4 +1,5 @@
 import { camelCase, kebabCase, pascalCase, snakeCase } from 'es-toolkit'
+import { casesExhausted } from '../../lib/prelude.js'
 import type { Config } from '../config/config.js'
 import {
   createCodeGenerator,
@@ -61,7 +62,16 @@ export const getFileName = (config: Config, generator: ModuleGenerator | Generat
 
 export const getImportName = (config: Config, generator: ModuleGenerator | GeneratedModule) => {
   const name = getBaseName(config, generator)
-  return `${name}.js`
+  switch (config.importFormat) {
+    case `jsExtension`:
+      return `${name}.js`
+    case `tsExtension`:
+      return `${name}.ts`
+    case `noExtension`:
+      return name
+    default:
+      throw casesExhausted(config.importFormat)
+  }
 }
 
 export const caseFormatters = {