Added support for BigInt to API routes

packages/next/build/babel/preset.ts

@@ -177,6 +177,7 @@ module.exports = (
       ],
       require('@babel/plugin-proposal-optional-chaining'),
       require('@babel/plugin-proposal-nullish-coalescing-operator'),
+      isServer && require('@babel/plugin-syntax-bigint'),
     ].filter(Boolean),
   }
 }

packages/next/package.json

@@ -63,6 +63,7 @@
     "@babel/plugin-proposal-nullish-coalescing-operator": "7.7.4",
     "@babel/plugin-proposal-object-rest-spread": "7.6.2",
     "@babel/plugin-proposal-optional-chaining": "7.7.4",
+    "@babel/plugin-syntax-bigint": "7.8.3",
     "@babel/plugin-syntax-dynamic-import": "7.2.0",
     "@babel/plugin-transform-modules-commonjs": "7.7.0",
     "@babel/plugin-transform-runtime": "7.6.2",

test/integration/bigint/pages/api/bigint.js

@@ -0,0 +1,4 @@
+export default (req, res) => {
+  res.statusCode = 200
+  res.send((1n + 2n).toString())
+}

test/integration/bigint/test/index.test.js

@@ -0,0 +1,77 @@
+/* eslint-env jest */
+/* global jasmine */
+import fs from 'fs-extra'
+import { join } from 'path'
+import {
+  fetchViaHTTP,
+  launchApp,
+  nextBuild,
+  nextStart,
+  killApp,
+  findPort,
+} from 'next-test-utils'
+
+jasmine.DEFAULT_TIMEOUT_INTERVAL = 1000 * 60 * 2
+
+const appDir = join(__dirname, '..')
+const nextConfig = join(appDir, 'next.config.js')
+let appPort
+let app
+
+const runTests = () => {
+  it('should return 200', async () => {
+    const res = await fetchViaHTTP(appPort, '/api/bigint', null, {
+      method: 'GET',
+    })
+    expect(res.status).toEqual(200)
+  })
+
+  it('should return the BigInt result text', async () => {
+    const resText = await fetchViaHTTP(appPort, '/api/bigint', null, {
+      method: 'GET',
+    }).then(res => res.ok && res.text())
+    expect(resText).toEqual('3')
+  })
+}
+
+describe('bigint API route support', () => {
+  describe('dev mode', () => {
+    beforeAll(async () => {
+      appPort = await findPort()
+      app = await launchApp(appDir, appPort)
+    })
+    afterAll(() => killApp(app))
+
+    runTests()
+  })
+
+  describe('server mode', () => {
+    beforeAll(async () => {
+      await fs.remove(nextConfig)
+      await nextBuild(appDir)
+      appPort = await findPort()
+      app = await nextStart(appDir, appPort)
+    })
+    afterAll(() => killApp(app))
+
+    runTests()
+  })
+
+  describe('serverless mode', () => {
+    beforeAll(async () => {
+      await fs.writeFile(
+        nextConfig,
+        `module.exports = { target: 'serverless' }`
+      )
+      await nextBuild(appDir)
+      appPort = await findPort()
+      app = await nextStart(appDir, appPort)
+    })
+    afterAll(async () => {
+      await killApp(app)
+      await fs.remove(nextConfig)
+    })
+
+    runTests()
+  })
+})

yarn.lock

@@ -220,6 +220,11 @@
   resolved "https://registry.yarnpkg.com/@babel/helper-plugin-utils/-/helper-plugin-utils-7.0.0.tgz#bbb3fbee98661c569034237cc03967ba99b4f250"
   integrity sha512-CYAOUCARwExnEixLdB6sDm2dIJ/YgEAKDM1MOeMeZu9Ld/bDgVo8aiWrXwcY7OBh+1Ea2uUcVRcxKk0GJvW7QA==
 
+"@babel/helper-plugin-utils@^7.8.0":
+  version "7.8.3"
+  resolved "https://registry.npmjs.org/@babel/helper-plugin-utils/-/helper-plugin-utils-7.8.3.tgz#9ea293be19babc0f52ff8ca88b34c3611b208670"
+  integrity sha512-j+fq49Xds2smCUNYmEHF9kGNkhbet6yVIBp4e6oeQpH1RUs/Ir06xUKzDjDkGcaaokPiTNs2JBWHjaE4csUkZQ==
+
 "@babel/helper-regex@^7.0.0", "@babel/helper-regex@^7.4.4":
   version "7.5.5"
   resolved "https://registry.yarnpkg.com/@babel/helper-regex/-/helper-regex-7.5.5.tgz#0aa6824f7100a2e0e89c1527c23936c152cab351"
@@ -384,6 +389,13 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.0.0"
 
+"@babel/plugin-syntax-bigint@7.8.3":
+  version "7.8.3"
+  resolved "https://registry.npmjs.org/@babel/plugin-syntax-bigint/-/plugin-syntax-bigint-7.8.3.tgz#4c9a6f669f5d0cdf1b90a1671e9a146be5300cea"
+  integrity sha512-wnTnFlG+YxQm3vDxpGE57Pj0srRU4sHE/mDkt1qv2YJJSeUAec2ma4WLUnUPeKjyrfntVwe/N6dCXpU+zL3Npg==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.8.0"
+
 "@babel/plugin-syntax-dynamic-import@7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-dynamic-import/-/plugin-syntax-dynamic-import-7.2.0.tgz#69c159ffaf4998122161ad8ebc5e6d1f55df8612"