feat: add check-update command (#881)

closes #876
- add check-update command to check for available updates

lib/commands/check-update.js

@@ -0,0 +1,34 @@
+const Command = require('../command');
+
+class CheckUpdateCommand extends Command {
+    run({v1}) {
+        const semver = require('semver');
+        const resolveVersion = require('../utils/resolve-version');
+        const {CliError} = require('../errors');
+
+        const instance = this.system.getInstance();
+
+        if (instance.version) {
+            return resolveVersion(null, instance.version, v1).then((version) => {
+                const diff = semver.diff(instance.version, version);
+                this.ui.log(`New ${diff} version available: ${version}`);
+            }).catch((error) => {
+                if (!(error instanceof CliError) || !error.message.match(/No valid versions/)) {
+                    return Promise.reject(error);
+                }
+            });
+        }
+    }
+}
+
+CheckUpdateCommand.description = 'Check if an update is available for a Ghost installation';
+CheckUpdateCommand.allowRoot = true;
+CheckUpdateCommand.options = {
+    v1: {
+        describe: 'Limit check to Ghost 1.x releases',
+        type: 'boolean',
+        default: false
+    }
+};
+
+module.exports = CheckUpdateCommand;

test/unit/commands/check-update-spec.js

@@ -0,0 +1,84 @@
+const sinon = require('sinon');
+const proxyquire = require('proxyquire');
+const {expect} = require('chai');
+const {CliError} = require('../../../lib/errors');
+
+const modulePath = '../../../lib/commands/check-update';
+
+describe('Unit: Commands > check-update', function () {
+    it('doesn\'t output anything if instance doesn\'t exist', function () {
+        const CheckUpdateCommand = require(modulePath);
+        const log = sinon.stub();
+        const getInstance = sinon.stub().returns({version: null});
+
+        const cmd = new CheckUpdateCommand({log}, {getInstance});
+
+        cmd.run({v1: false});
+
+        expect(getInstance.calledOnce).to.be.true;
+        expect(log.called).to.be.false;
+    });
+
+    it('doesn\'t output anything if no new versions are available', function () {
+        const resolveVersion = sinon.stub().rejects(new CliError('No valid versions found.'));
+
+        const CheckUpdateCommand = proxyquire(modulePath, {
+            '../utils/resolve-version': resolveVersion
+        });
+
+        const log = sinon.stub();
+        const getInstance = sinon.stub().returns({version: '2.0.0'});
+
+        const cmd = new CheckUpdateCommand({log}, {getInstance});
+
+        return cmd.run({v1: false}).then(() => {
+            expect(getInstance.calledOnce).to.be.true;
+            expect(resolveVersion.calledOnce).to.be.true;
+            expect(resolveVersion.calledWithExactly(null, '2.0.0', false)).to.be.true;
+            expect(log.called).to.be.false;
+        });
+    });
+
+    it('rejects errors from resolveVersion', function () {
+        const resolveVersion = sinon.stub().rejects(new CliError('An error occurred'));
+
+        const CheckUpdateCommand = proxyquire(modulePath, {
+            '../utils/resolve-version': resolveVersion
+        });
+
+        const log = sinon.stub();
+        const getInstance = sinon.stub().returns({version: '2.0.0'});
+
+        const cmd = new CheckUpdateCommand({log}, {getInstance});
+
+        return cmd.run({v1: true}).then(() => {
+            expect(false, 'error should have been thrown').to.be.false;
+        }).catch((error) => {
+            expect(error).to.be.an.instanceof(CliError);
+            expect(getInstance.calledOnce).to.be.true;
+            expect(resolveVersion.calledOnce).to.be.true;
+            expect(resolveVersion.calledWithExactly(null, '2.0.0', true)).to.be.true;
+            expect(log.called).to.be.false;
+        });
+    });
+
+    it('logs out available new version', function () {
+        const resolveVersion = sinon.stub().resolves('2.1.0');
+
+        const CheckUpdateCommand = proxyquire(modulePath, {
+            '../utils/resolve-version': resolveVersion
+        });
+
+        const log = sinon.stub();
+        const getInstance = sinon.stub().returns({version: '2.0.0'});
+
+        const cmd = new CheckUpdateCommand({log}, {getInstance});
+
+        return cmd.run({v1: true}).then(() => {
+            expect(getInstance.calledOnce).to.be.true;
+            expect(resolveVersion.calledOnce).to.be.true;
+            expect(resolveVersion.calledWithExactly(null, '2.0.0', true)).to.be.true;
+            expect(log.calledOnce).to.be.true;
+        });
+    });
+});