Allow, but warn for, pre-release versions of Node (#23970)

* Allow, but warn for, pre-release versions of Node

* Add tests

* Re-add commented-out warning for next EOL Node version

Author: ascorbic

packages/gatsby-cli/src/__tests__/index.js

@@ -58,6 +58,20 @@ describe(`error handling`, () => {
       expect.stringContaining(`https://gatsby.dev/upgrading-node-js`)
     )
   })
+
+  it(`allows prerelease versions`, () => {
+    const { reporter } = setup(`v15.0.0-pre`)
+
+    expect(reporter.panic).not.toHaveBeenCalled()
+  })
+
+  it(`warns on prerelease versions`, () => {
+    const { reporter } = setup(`v15.0.0-pre`)
+
+    expect(reporter.warn).toHaveBeenCalledWith(
+      expect.stringContaining(`prerelease`)
+    )
+  })
 })
 
 // describe(`deprecation warning`, () => {

packages/gatsby-cli/src/index.ts

@@ -27,19 +27,34 @@ updateNotifier({ pkg }).notify({ isGlobal: true })
 const MIN_NODE_VERSION = `10.13.0`
 // const NEXT_MIN_NODE_VERSION = `10.13.0`
 
-if (!semver.satisfies(process.version, `>=${MIN_NODE_VERSION}`)) {
+const { version } = process
+
+if (
+  !semver.satisfies(version, `>=${MIN_NODE_VERSION}`, {
+    includePrerelease: true,
+  })
+) {
   report.panic(
     report.stripIndent(`
-      Gatsby requires Node.js ${MIN_NODE_VERSION} or higher (you have ${process.version}).
+      Gatsby requires Node.js ${MIN_NODE_VERSION} or higher (you have ${version}).
       Upgrade Node to the latest stable release: https://gatsby.dev/upgrading-node-js
     `)
   )
 }
 
-// if (!semver.satisfies(process.version, `>=${NEXT_MIN_NODE_VERSION}`)) {
+if (semver.prerelease(version)) {
+  report.warn(
+    report.stripIndent(`
+    You are currently using a prerelease version of Node (${version}), which is not supported.
+    You can use this for testing, but we do not recommend it in production. 
+    Before reporting any bugs, please test with a supported version of Node (>=${MIN_NODE_VERSION}).`)
+  )
+}
+
+// if (!semver.satisfies(version, `>=${NEXT_MIN_NODE_VERSION}`)) {
 //   report.warn(
 //     report.stripIndent(`
-//       Node.js ${process.version} has reached End of Life status on 31 December, 2019.
+//       Node.js ${version} has reached End of Life status on 31 December, 2019.
 //       Gatsby will only actively support ${NEXT_MIN_NODE_VERSION} or higher and drop support for Node 8 soon.
 //       Please upgrade Node.js to a currently active LTS release: https://gatsby.dev/upgrading-node-js
 //     `)