refactor: java checks (#1130)

Co-authored-by: エリス <erisu@users.noreply.github.com>
Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

Update spec/unit/java.spec.js

Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

Update spec/unit/java.spec.js

Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

Update bin/templates/cordova/lib/utils.js

Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

Update bin/templates/cordova/lib/check_reqs.js

Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

Update spec/unit/check_reqs.spec.js

Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

Update spec/unit/check_reqs.spec.js

Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

bin/templates/cordova/lib/check_reqs.js

@@ -20,30 +20,20 @@
 const execa = require('execa');
 var path = require('path');
 var fs = require('fs-extra');
-var os = require('os');
+const { forgivingWhichSync, isWindows, isDarwin } = require('./utils');
-var which = require('which');
+const java = require('./env/java');
-const glob = require('fast-glob');
 var REPO_ROOT = path.join(__dirname, '..', '..', '..', '..');
 var PROJECT_ROOT = path.join(__dirname, '..', '..');
 const { CordovaError, ConfigParser, events } = require('cordova-common');
 var android_sdk = require('./android_sdk');
 const { createEditor } = require('properties-parser');
+const semver = require('semver');
 
-function forgivingWhichSync (cmd) {
+const EXPECTED_JAVA_VERSION = '1.8.x';
-    const whichResult = which.sync(cmd, { nothrow: true });
 
-    // On null, returns empty string to maintain backwards compatibility
+// Re-exporting these for backwards compatibility and for unit testing.
-    // realpathSync follows symlinks
+// TODO: Remove uses and use the ./utils module directly.
-    return whichResult === null ? '' : fs.realpathSync(whichResult);
+Object.assign(module.exports, { isWindows, isDarwin });
-}
-
-module.exports.isWindows = function () {
-    return (os.platform() === 'win32');
-};
-
-module.exports.isDarwin = function () {
-    return (os.platform() === 'darwin');
-};
 
 /**
  * @description Get valid target from framework/project.properties if run from this repo
@@ -143,72 +133,18 @@ module.exports.check_gradle = function () {
                             'in your path, or install Android Studio'));
 };
 
-// Returns a promise.
+/**
-module.exports.check_java = function () {
+ * Checks for the java installation and correct version
-    var javacPath = forgivingWhichSync('javac');
+ */
-    var hasJavaHome = !!process.env.JAVA_HOME;
+module.exports.check_java = async function () {
-    return Promise.resolve().then(function () {
+    const javaVersion = await java.getVersion();
-        if (hasJavaHome) {
-            // Windows java installer doesn't add javac to PATH, nor set JAVA_HOME (ugh).
-            if (!javacPath) {
-                process.env.PATH += path.delimiter + path.join(process.env.JAVA_HOME, 'bin');
-            }
-        } else {
-            if (javacPath) {
-                // OS X has a command for finding JAVA_HOME.
-                var find_java = '/usr/libexec/java_home';
-                var default_java_error_msg = 'Failed to find \'JAVA_HOME\' environment variable. Try setting it manually.';
-                if (fs.existsSync(find_java)) {
-                    return execa(find_java).then(({ stdout }) => {
-                        process.env.JAVA_HOME = stdout;
-                    }).catch(function (err) {
-                        if (err) {
-                            throw new CordovaError(default_java_error_msg);
-                        }
-                    });
-                } else {
-                    // See if we can derive it from javac's location.
-                    var maybeJavaHome = path.dirname(path.dirname(javacPath));
-                    if (fs.existsSync(path.join(maybeJavaHome, 'lib', 'tools.jar'))) {
-                        process.env.JAVA_HOME = maybeJavaHome;
-                    } else {
-                        throw new CordovaError(default_java_error_msg);
-                    }
-                }
-            } else if (module.exports.isWindows()) {
-                const { env } = process;
-                const baseDirs = [env.ProgramFiles, env['ProgramFiles(x86)']];
-                const globOpts = { absolute: true, onlyDirectories: true };
-                const flatMap = (arr, f) => [].concat(...arr.map(f));
 
-                const jdkDir = flatMap(baseDirs, cwd =>
+    if (!semver.satisfies(javaVersion.version, EXPECTED_JAVA_VERSION)) {
-                    glob.sync('java/jdk*', { cwd, ...globOpts })
+        throw new CordovaError(
-                )[0];
+            `Requirements check failed for JDK ${EXPECTED_JAVA_VERSION}! Detected version: ${javaVersion.version}\n` +
-
+            'Check your ANDROID_SDK_ROOT / JAVA_HOME / PATH environment variables.'
-                if (jdkDir) {
+        );
-                    env.PATH += path.delimiter + path.join(jdkDir, 'bin');
-                    env.JAVA_HOME = path.normalize(jdkDir);
     }
-            }
-        }
-    }).then(function () {
-        return execa('javac', ['-version'], { all: true })
-            .then(({ all: output }) => {
-                // Java <= 8 writes version info to stderr, Java >= 9 to stdout
-                const match = /javac\s+([\d.]+)/i.exec(output);
-                return match && match[1];
-            }, () => {
-                var msg =
-                'Failed to run "javac -version", make sure that you have a JDK version 8 installed.\n' +
-                'You can get it from the following location:\n' +
-                'https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html';
-                if (process.env.JAVA_HOME) {
-                    msg += '\n\n';
-                    msg += 'Your JAVA_HOME is invalid: ' + process.env.JAVA_HOME;
-                }
-                throw new CordovaError(msg);
-            });
-    });
 };
 
 // Returns a promise.
@@ -384,13 +320,6 @@ module.exports.run = function () {
     return Promise.all([this.check_java(), this.check_android()]).then(function (values) {
         console.log('Using Android SDK: ' + process.env.ANDROID_SDK_ROOT);
 
-        if (!String(values[0]).startsWith('1.8.')) {
-            throw new CordovaError(
-                'Requirements check failed for JDK 8 (\'1.8.*\')! Detected version: ' + values[0] + '\n' +
-                'Check your ANDROID_SDK_ROOT / JAVA_HOME / PATH environment variables.'
-            );
-        }
-
         if (!values[1]) {
             throw new CordovaError('Requirements check failed for Android SDK! Android SDK was not detected.');
         }

bin/templates/cordova/lib/env/java.js

@@ -0,0 +1,123 @@
+/*
+       Licensed to the Apache Software Foundation (ASF) under one
+       or more contributor license agreements.  See the NOTICE file
+       distributed with this work for additional information
+       regarding copyright ownership.  The ASF licenses this file
+       to you under the Apache License, Version 2.0 (the
+       "License"); you may not use this file except in compliance
+       with the License.  You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+       Unless required by applicable law or agreed to in writing,
+       software distributed under the License is distributed on an
+       "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+       KIND, either express or implied.  See the License for the
+       specific language governing permissions and limitations
+       under the License.
+*/
+
+const execa = require('execa');
+const fs = require('fs-extra');
+const path = require('path');
+const glob = require('fast-glob');
+const { CordovaError, events } = require('cordova-common');
+const utils = require('../utils');
+const semver = require('semver');
+
+/**
+ * Will be set to true on successful ensureness.
+ * If true, skips the expensive java checks.
+ */
+let javaIsEnsured = false;
+
+const java = {
+    /**
+     * Gets the version from the javac executable.
+     *
+     * @returns {semver.SemVer}
+     */
+    getVersion: async () => {
+        await java._ensure(process.env);
+
+        // Java <= 8 writes version info to stderr, Java >= 9 to stdout
+        let version = null;
+        try {
+            version = (await execa('javac', ['-version'], { all: true })).all;
+        } catch (ex) {
+            events.emit('verbose', ex.shortMessage);
+
+            let msg =
+            'Failed to run "javac -version", make sure that you have a JDK version 8 installed.\n' +
+            'You can get it from the following location:\n' +
+            'https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html';
+            if (process.env.JAVA_HOME) {
+                msg += '\n\n';
+                msg += 'Your JAVA_HOME is invalid: ' + process.env.JAVA_HOME;
+            }
+            throw new CordovaError(msg);
+        }
+
+        return semver.coerce(version);
+    },
+
+    /**
+     * Ensures that Java is installed. Will throw exception if not.
+     * Will set JAVA_HOME and PATH environment variables.
+     *
+     * This function becomes a no-op if already ran previously.
+     */
+    _ensure: async (environment) => {
+        if (javaIsEnsured) {
+            return;
+        }
+
+        const javacPath = utils.forgivingWhichSync('javac');
+        const hasJavaHome = !!environment.JAVA_HOME;
+        if (hasJavaHome) {
+            // Windows java installer doesn't add javac to PATH, nor set JAVA_HOME (ugh).
+            if (!javacPath) {
+                environment.PATH += path.delimiter + path.join(environment.JAVA_HOME, 'bin');
+            }
+        } else {
+            if (javacPath) {
+                // OS X has a command for finding JAVA_HOME.
+                const find_java = '/usr/libexec/java_home';
+                const default_java_error_msg = 'Failed to find \'JAVA_HOME\' environment variable. Try setting it manually.';
+                if (fs.existsSync(find_java)) {
+                    try {
+                        environment.JAVA_HOME = (await execa(find_java)).stdout;
+                    } catch (ex) {
+                        events.emit('verbose', ex.shortMessage);
+                        throw new CordovaError(default_java_error_msg);
+                    }
+                } else {
+                    // See if we can derive it from javac's location.
+                    var maybeJavaHome = path.dirname(path.dirname(javacPath));
+                    if (fs.existsSync(path.join(maybeJavaHome, 'lib', 'tools.jar'))) {
+                        environment.JAVA_HOME = maybeJavaHome;
+                    } else {
+                        throw new CordovaError(default_java_error_msg);
+                    }
+                }
+            } else if (utils.isWindows()) {
+                const baseDirs = [environment.ProgramFiles, environment['ProgramFiles(x86)']];
+                const globOpts = { absolute: true, onlyDirectories: true };
+                const flatMap = (arr, f) => [].concat(...arr.map(f));
+                const jdkDir = flatMap(baseDirs, cwd => {
+                    return glob.sync('java/jdk*', { cwd, ...globOpts });
+                }
+                )[0];
+
+                if (jdkDir) {
+                    environment.PATH += path.delimiter + path.join(jdkDir, 'bin');
+                    environment.JAVA_HOME = path.normalize(jdkDir);
+                }
+            }
+        }
+
+        javaIsEnsured = true;
+    }
+};
+
+module.exports = java;

bin/templates/cordova/lib/utils.js

@@ -24,6 +24,8 @@
 // TODO: Perhaps this should live in cordova-common?
 
 const fs = require('fs-extra');
+const which = require('which');
+const os = require('os');
 
 /**
  * Reads, searches, and replaces the found occurences with replacementString and then writes the file back out.
@@ -53,3 +55,14 @@ exports.compareByAll = fns => {
         return 0;
     };
 };
+
+exports.forgivingWhichSync = (cmd) => {
+    const whichResult = which.sync(cmd, { nothrow: true });
+
+    // On null, returns empty string to maintain backwards compatibility
+    // realpathSync follows symlinks
+    return whichResult === null ? '' : fs.realpathSync(whichResult);
+};
+
+exports.isWindows = () => os.platform() === 'win32';
+exports.isDarwin = () => os.platform() === 'darwin';

package-lock.json

@@ -62,6 +62,12 @@
             "chalk": "^2.0.0",
             "js-tokens": "^4.0.0"
           }
+        },
+        "semver": {
+          "version": "5.7.1",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
+          "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ==",
+          "dev": true
         }
       }
     },
@@ -481,6 +487,13 @@
       "integrity": "sha512-/GWUAqa2OJNlDF5VGSe3SR1QMHEPXxx54Ur56r0qQC0H9FlBr7kyBF2SgVEhzFCPbrW4UcYgVuWrq/2Ty3QvXg==",
       "requires": {
         "semver": "^5.4.1"
+      },
+      "dependencies": {
+        "semver": {
+          "version": "5.7.1",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
+          "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ=="
+        }
       }
     },
     "ansi": {
@@ -2122,6 +2135,14 @@
       "integrity": "sha1-+wMJF/hqMTTlvJvsDWngAT3f7bI=",
       "dev": true
     },
+    "lru-cache": {
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-6.0.0.tgz",
+      "integrity": "sha512-Jo6dJ04CmSjuznwJSS3pUeWmd/H0ffTlkXXgwZi+eq1UCmqQwCh+eLsYOYCwY991i2Fah4h1BEMCx4qThGbsiA==",
+      "requires": {
+        "yallist": "^4.0.0"
+      }
+    },
     "make-dir": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/make-dir/-/make-dir-3.1.0.tgz",
@@ -2238,6 +2259,14 @@
         "resolve": "^1.10.0",
         "semver": "2 || 3 || 4 || 5",
         "validate-npm-package-license": "^3.0.1"
+      },
+      "dependencies": {
+        "semver": {
+          "version": "5.7.1",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
+          "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ==",
+          "dev": true
+        }
       }
     },
     "npm-run-path": {
@@ -2771,9 +2800,12 @@
       "integrity": "sha1-dLbTPJrh4AFRDxeakRaFiPGu2qk="
     },
     "semver": {
-      "version": "5.7.1",
+      "version": "7.3.4",
-      "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
+      "resolved": "https://registry.npmjs.org/semver/-/semver-7.3.4.tgz",
-      "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ=="
+      "integrity": "sha512-tCfb2WLjqFAtXn4KEdxIhalnRtoKFN7nAwj0B3ZXCbQloV2tq5eDbcTmT68JJD3nRJq24/XgxtQKFIpQdtvmVw==",
+      "requires": {
+        "lru-cache": "^6.0.0"
+      }
     },
     "set-blocking": {
       "version": "2.0.0",
@@ -3271,6 +3303,11 @@
       "integrity": "sha512-r9S/ZyXu/Xu9q1tYlpsLIsa3EeLXXk0VwlxqTcFRfg9EhMW+17kbt9G0NrgCmhGb5vT2hyhJZLfDGx+7+5Uj/w==",
       "dev": true
     },
+    "yallist": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/yallist/-/yallist-4.0.0.tgz",
+      "integrity": "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A=="
+    },
     "yargs": {
       "version": "15.3.1",
       "resolved": "https://registry.npmjs.org/yargs/-/yargs-15.3.1.tgz",

package.json

@@ -33,6 +33,7 @@
     "is-path-inside": "^3.0.2",
     "nopt": "^4.0.3",
     "properties-parser": "^0.3.1",
+    "semver": "^7.3.4",
     "which": "^2.0.2"
   },
   "devDependencies": {

spec/unit/check_reqs.spec.js

@@ -19,11 +19,11 @@
 
 var rewire = require('rewire');
 var android_sdk = require('../../bin/templates/cordova/lib/android_sdk');
-var os = require('os');
 var fs = require('fs-extra');
 var path = require('path');
 var events = require('cordova-common').events;
 var which = require('which');
+const { CordovaError } = require('cordova-common');
 
 // This should match /bin/templates/project/build.gradle
 const DEFAULT_TARGET_API = 29;
@@ -48,33 +48,13 @@ describe('check_reqs', function () {
     });
 
     describe('check_java', () => {
-        let tmpDir;
+        it('detects if unexpected JDK version is installed', async () => {
-        beforeEach(() => {
-            const tmpDirTemplate = path.join(os.tmpdir(), 'cordova-android-test-');
-            tmpDir = fs.realpathSync(fs.mkdtempSync(tmpDirTemplate));
-        });
-        afterEach(() => {
-            fs.removeSync(tmpDir);
-        });
-
-        it('detects JDK in default location on windows', async () => {
-            check_reqs.isWindows = () => true;
             check_reqs.__set__({
-                execa: async () => ({}),
+                EXPECTED_JAVA_VERSION: '9999.9999.9999',
-                forgivingWhichSync: () => ''
+                java: { getVersion: async () => ({ version: '1.8.0' }) }
             });
 
-            delete process.env.JAVA_HOME;
+            await expectAsync(check_reqs.check_java()).toBeRejectedWithError(CordovaError, /Requirements check failed for JDK 9999.9999.9999! Detected version: 1.8.0/);
-            process.env.ProgramFiles = tmpDir;
-
-            const jdkDir = path.join(tmpDir, 'java/jdk1.6.0_02');
-            fs.ensureDirSync(jdkDir);
-
-            await check_reqs.check_java();
-
-            expect(process.env.JAVA_HOME).toBe(jdkDir);
-            expect(process.env.PATH.split(path.delimiter))
-                .toContain(path.join(jdkDir, 'bin'));
         });
     });
 

spec/unit/java.spec.js

@@ -0,0 +1,177 @@
+/**
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you under the Apache License, Version 2.0 (the
+    "License"); you may not use this file except in compliance
+    with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing,
+    software distributed under the License is distributed on an
+    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+    KIND, either express or implied.  See the License for the
+    specific language governing permissions and limitations
+    under the License.
+*/
+
+const path = require('path');
+const rewire = require('rewire');
+const { CordovaError } = require('cordova-common');
+const utils = require('../../bin/templates/cordova/lib/utils');
+const glob = require('fast-glob');
+
+describe('Java', () => {
+    const Java = rewire('../../bin/templates/cordova/lib/env/java');
+
+    describe('getVersion', () => {
+        let originalEnsureFunc = null;
+
+        beforeEach(() => {
+            /*
+                This is to avoid changing/polluting the
+                process environment variables
+                as a result of running these java tests; which could produce
+                unexpected side effects to other tests.
+             */
+            originalEnsureFunc = Java._ensure;
+            spyOn(Java, '_ensure').and.callFake(() => {
+                return originalEnsureFunc({});
+            });
+        });
+
+        it('runs', async () => {
+            Java.__set__('execa', () => Promise.resolve({
+                all: 'javac 1.8.0_275'
+            }));
+
+            console.log('BEFORE', process.env.JAVA_HOME);
+            const result = await Java.getVersion();
+            console.log('AFTER', process.env.JAVA_HOME);
+            expect(result.major).toBe(1);
+            expect(result.minor).toBe(8);
+            expect(result.patch).toBe(0);
+            expect(result.version).toBe('1.8.0');
+        });
+
+        it('produces a CordovaError on error', async () => {
+            Java.__set__('execa', () => Promise.reject({
+                shortMessage: 'test error'
+            }));
+            const emitSpy = jasmine.createSpy('events.emit');
+            Java.__set__('events', {
+                emit: emitSpy
+            });
+
+            await expectAsync(Java.getVersion())
+                .toBeRejectedWithError(CordovaError, /Failed to run "javac -version"/);
+            expect(emitSpy).toHaveBeenCalledWith('verbose', 'test error');
+        });
+    });
+
+    describe('_ensure', () => {
+        beforeEach(() => {
+            Java.__set__('javaIsEnsured', false);
+        });
+
+        it('with JAVA_HOME / without javac', async () => {
+            spyOn(utils, 'forgivingWhichSync').and.returnValue('');
+
+            const env = {
+                JAVA_HOME: '/tmp/jdk'
+            };
+
+            await Java._ensure(env);
+
+            expect(env.PATH.split(path.delimiter))
+                .toContain(path.join(env.JAVA_HOME, 'bin'));
+        });
+
+        it('detects JDK in default location on windows', async () => {
+            spyOn(utils, 'forgivingWhichSync').and.returnValue('');
+            spyOn(utils, 'isWindows').and.returnValue(true);
+
+            const root = 'C:\\Program Files';
+            const env = {
+                ProgramFiles: root
+            };
+
+            spyOn(glob, 'sync').and.returnValue(`${root}\\java\\jdk1.8.0_275`);
+
+            const jdkDir = `${root}\\java\\jdk1.8.0_275`;
+
+            await Java._ensure(env);
+
+            expect(env.JAVA_HOME).withContext('JAVA_HOME').toBe(jdkDir);
+            expect(env.PATH).toContain(jdkDir);
+        });
+
+        it('detects JDK in default location on windows (x86)', async () => {
+            spyOn(utils, 'forgivingWhichSync').and.returnValue('');
+            spyOn(utils, 'isWindows').and.returnValue(true);
+
+            const root = 'C:\\Program Files (x86)';
+            const env = {
+                'ProgramFiles(x86)': root
+            };
+
+            spyOn(glob, 'sync').and.returnValue(`${root}\\java\\jdk1.8.0_275`);
+
+            const jdkDir = `${root}\\java\\jdk1.8.0_275`;
+
+            await Java._ensure(env);
+
+            expect(env.JAVA_HOME).withContext('JAVA_HOME').toBe(jdkDir);
+            expect(env.PATH).toContain(jdkDir);
+        });
+
+        it('without JAVA_HOME / with javac - Mac OS X - success', async () => {
+            spyOn(utils, 'forgivingWhichSync').and.returnValue('/tmp/jdk/bin');
+            const fsSpy = jasmine.createSpy('fs').and.returnValue(true);
+            Java.__set__('fs', {
+                existsSync: fsSpy
+            });
+            Java.__set__('execa', async () => ({ stdout: '/tmp/jdk' }));
+
+            const env = {};
+
+            await Java._ensure(env);
+
+            expect(fsSpy).toHaveBeenCalledWith('/usr/libexec/java_home');
+            expect(env.JAVA_HOME).toBe('/tmp/jdk');
+        });
+
+        it('without JAVA_HOME / with javac - Mac OS X - error', async () => {
+            spyOn(utils, 'forgivingWhichSync').and.returnValue('/tmp/jdk/bin');
+            Java.__set__('fs', { existsSync: () => true });
+            Java.__set__('execa', jasmine.createSpy('execa').and.returnValue(Promise.reject({
+                shortMessage: 'test error'
+            })));
+            const emitSpy = jasmine.createSpy('events.emit');
+            Java.__set__('events', {
+                emit: emitSpy
+            });
+
+            await expectAsync(Java._ensure({}))
+                .toBeRejectedWithError(CordovaError, /Failed to find 'JAVA_HOME' environment variable/);
+
+            expect(emitSpy).toHaveBeenCalledWith('verbose', 'test error');
+        });
+
+        it('derive from javac location - success', async () => {
+            spyOn(utils, 'forgivingWhichSync').and.returnValue('/tmp/jdk/bin');
+            Java.__set__('fs', { existsSync: path => !/java_home$/.test(path) });
+            const env = {};
+            await Java._ensure(env);
+            expect(env.JAVA_HOME).toBe('/tmp');
+        });
+
+        it('derive from javac location - error', async () => {
+            spyOn(utils, 'forgivingWhichSync').and.returnValue('/tmp/jdk/bin');
+            Java.__set__('fs', { existsSync: () => false });
+            await expectAsync(Java._ensure({})).toBeRejectedWithError(CordovaError, /Failed to find 'JAVA_HOME' environment variable/);
+        });
+    });
+});