feat(js-client): add type definitions (#6009)

* feat(js-client): add type definitions

Add type definitions for dynamic client methods by defining the
NetlifyAPI class as an interface that inherits mapped types.

* feat(js-client): treat path params and query params as one object

The api client methods will assign these to the correct places but just
accept the params as a single object.

* fix(js-client): update accessToken type to allow undefined

The api response for accessToken can possibly be undefined but we were
only allowing string or null before.

* feat(js-client): handle snake_case and camelCase params in type definitions

Since the API client allows using camelCased params we need to allow
these to keep backwards compatibility.

packages/js-client/src/index.ts

@@ -3,6 +3,7 @@ import pWaitFor from 'p-wait-for'
 import { getMethods } from './methods/index.js'
 import { openApiSpec } from './open_api.js'
 import { getOperations } from './operations.js'
+import type { DynamicMethods } from './types.js'
 
 // 1 second
 const DEFAULT_TICKET_POLL = 1e3
@@ -28,8 +29,11 @@ type APIOptions = {
   globalParams?: Record<string, unknown>
 }
 
+// eslint-disable-next-line @typescript-eslint/no-empty-interface -- NetlifyAPI is a class and the interface just inherits mapped types
+export interface NetlifyAPI extends DynamicMethods {}
+
 export class NetlifyAPI {
-  #accessToken: string | null = null
+  #accessToken: string | undefined | null = null
 
   defaultHeaders: Record<string, string> = {
     accept: 'application/json',
@@ -66,11 +70,11 @@ export class NetlifyAPI {
   }
 
   /** Retrieves the access token */
-  get accessToken(): string | null {
+  get accessToken(): string | undefined | null {
     return this.#accessToken
   }
 
-  set accessToken(token: string | null) {
+  set accessToken(token: string | undefined | null) {
     if (!token) {
       delete this.defaultHeaders.Authorization
       this.#accessToken = null
@@ -108,18 +112,6 @@ export class NetlifyAPI {
     this.accessToken = accessTokenResponse.access_token
     return accessTokenResponse.access_token
   }
-
-  // Those methods are getting implemented by the Object.assign(this, { ...methods }) in the constructor
-  // This is a way where we can still maintain proper types while not implementing them.
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  showTicket(_config: { ticketId: string }): Promise<{ authorized: boolean }> {
-    throw new Error('Will be overridden in constructor!')
-  }
-
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  exchangeTicket(_config: { ticketId: string }): Promise<{ access_token: string }> {
-    throw new Error('Will be overridden in constructor!')
-  }
 }
 
 export const methods = getOperations()

packages/js-client/src/types.ts

@@ -0,0 +1,54 @@
+import type { operations } from '@netlify/open-api'
+
+/**
+ * Converts snake_case to camelCase for TypeScript types.
+ */
+type CamelCase<S extends string> = S extends `${infer T}_${infer U}` ? `${T}${Capitalize<CamelCase<U>>}` : S
+
+/**
+ * Creates a union of both snake_case and camelCase keys with their respective types.
+ */
+type SnakeToCamel<T> = {
+  [K in keyof T as CamelCase<K & string>]: T[K]
+}
+
+/**
+ * Combines snake_case and camelCase parameters.
+ */
+type CombinedCaseParams<T> = SnakeToCamel<T> | T
+
+/**
+ * Combines `path` and `query` parameters into a single type.
+ */
+type OperationParams<K extends keyof operations> = 'parameters' extends keyof operations[K]
+  ? 'path' extends keyof operations[K]['parameters']
+    ? 'query' extends keyof operations[K]['parameters']
+      ? CombinedCaseParams<
+          Omit<operations[K]['parameters']['path'], keyof operations[K]['parameters']['query']> &
+            operations[K]['parameters']['query']
+        >
+      : CombinedCaseParams<operations[K]['parameters']['path']>
+    : 'query' extends keyof operations[K]['parameters']
+      ? CombinedCaseParams<operations[K]['parameters']['query']>
+      : undefined
+  : undefined
+
+type SuccessHttpStatusCodes = 200 | 201 | 202 | 203 | 204 | 205 | 206 | 207 | 208 | 226
+/**
+ * Extracts the response type from the operation.
+ */
+type OperationResponse<K extends keyof operations> = 'responses' extends keyof operations[K]
+  ? SuccessHttpStatusCodes extends infer StatusKeys
+    ? StatusKeys extends keyof operations[K]['responses']
+      ? 'content' extends keyof operations[K]['responses'][StatusKeys]
+        ? 'application/json' extends keyof operations[K]['responses'][StatusKeys]['content']
+          ? operations[K]['responses'][StatusKeys]['content']['application/json']
+          : never
+        : never
+      : never
+    : never
+  : never
+
+export type DynamicMethods = {
+  [K in keyof operations]: (params: OperationParams<K>) => Promise<OperationResponse<K>>
+}