version.ts

import fs = require('fs');
import { Observable, combineLatest } from 'rxjs/';

const exec = require('child_process').exec;

const revision = new Observable<string>(s => {
    exec('git rev-parse HEAD',
        function (error: Error, stdout: Buffer, stderr: Buffer) {
            if (error !== null) {
                console.log('git error: ' + error + stderr);
            }
            s.next(stdout.toString().trim());
            s.complete();
        });
});

combineLatest(revision)
    // tslint:disable-next-line:no-shadowed-variable
    .subscribe(([revision]) => {
        console.log(`version: '${process.env.npm_package_version}', revision: '${revision}'`);
        const today = new Date().toISOString().slice(0, 10);
        const content = '// this file is automatically generated by version.ts script\n' +
            `export const versions = {version: '${process.env.npm_package_version}', revision: '${revision
            }', buildTime: '${today}'};\n`;

        fs.writeFileSync(
            'src/environments/versions.ts',
            content,
            { encoding: 'utf8' }
        );
    });