fix: JDK version check wouldn't detect JDK 8 correctly (#1395)

`envinfo` uses `javac -version` to work out the JDK version number. The doctor command was looking for a semver range of `>= 8` but this won't work for JDK 8 as it uses the old style numbering scheme (e.g. `1.8.x` not `8.x.x`). JDKs 9+ use the new version numbering scheme.

Fixes #1255

Author: liamjones

packages/cli/src/commands/doctor/healthchecks/__tests__/jdk.test.ts

@@ -40,10 +40,20 @@ describe('jdk', () => {
     expect(diagnostics.needsToBeFixed).toBe(true);
   });
 
-  it('returns false if JDK version is in range', async () => {
+  it('returns false if JDK version is in range (JDK 9+ version number format)', async () => {
     // @ts-ignore
     environmentInfo.Languages.Java = {
-      version: '9',
+      version: '9.0.4',
+    };
+
+    const diagnostics = await jdk.getDiagnostics(environmentInfo);
+    expect(diagnostics.needsToBeFixed).toBe(false);
+  });
+
+  it('returns false if JDK version is in range (JDK 8 version number format)', async () => {
+    // @ts-ignore
+    environmentInfo.Languages.Java = {
+      version: '1.8.0_282',
     };
 
     const diagnostics = await jdk.getDiagnostics(environmentInfo);

packages/cli/src/commands/doctor/versionRanges.ts

@@ -4,7 +4,7 @@ export default {
   YARN: '>= 1.10.x',
   NPM: '>= 4.x',
   WATCHMAN: '4.x',
-  JAVA: '>= 8',
+  JAVA: '1.8.x || >= 9',
   // Android
   ANDROID_SDK: '>= 26.x',
   ANDROID_NDK: '>= 19.x',