Support for OAuth 2.0 (#5)

plugins/auth-oauth2/src/getAccessToken.ts

@@ -0,0 +1,71 @@
+import { Context, HttpRequest, HttpUrlParameter } from '@yaakapp/api';
+import { readFileSync } from 'node:fs';
+import { AccessTokenRawResponse } from './store';
+
+export async function getAccessToken(
+  ctx: Context, {
+    accessTokenUrl,
+    scope,
+    params,
+    grantType,
+    credentialsInBody,
+    clientId,
+    clientSecret,
+  }: {
+    clientId: string;
+    clientSecret: string;
+    grantType: string;
+    accessTokenUrl: string;
+    scope: string | null;
+    credentialsInBody: boolean;
+    params: HttpUrlParameter[];
+  }): Promise<AccessTokenRawResponse> {
+  console.log('Getting access token', accessTokenUrl);
+  const httpRequest: Partial<HttpRequest> = {
+    method: 'POST',
+    url: accessTokenUrl,
+    bodyType: 'application/x-www-form-urlencoded',
+    body: {
+      form: [
+        { name: 'grant_type', value: grantType },
+        ...params,
+      ],
+    },
+    headers: [
+      { name: 'User-Agent', value: 'yaak' },
+      { name: 'Accept', value: 'application/x-www-form-urlencoded, application/json' },
+      { name: 'Content-Type', value: 'application/x-www-form-urlencoded' },
+    ],
+  };
+
+  if (scope) httpRequest.body!.form.push({ name: 'scope', value: scope });
+
+  if (credentialsInBody) {
+    httpRequest.body!.form.push({ name: 'client_id', value: clientId });
+    httpRequest.body!.form.push({ name: 'client_secret', value: clientSecret });
+  } else {
+    const value = 'Basic ' + Buffer.from(`${clientId}:${clientSecret}`).toString('base64');
+    httpRequest.headers!.push({ name: 'Authorization', value });
+  }
+
+  const resp = await ctx.httpRequest.send({ httpRequest });
+
+  if (resp.status < 200 || resp.status >= 300) {
+    throw new Error('Failed to fetch access token with status=' + resp.status);
+  }
+
+  const body = readFileSync(resp.bodyPath ?? '', 'utf8');
+
+  let response;
+  try {
+    response = JSON.parse(body);
+  } catch {
+    response = Object.fromEntries(new URLSearchParams(body));
+  }
+
+  if (response.error) {
+    throw new Error('Failed to fetch access token with ' + response.error);
+  }
+
+  return response;
+}