Browsersync with proxy for Spring Boot REST API

gulpfile.js

var gulp            = require('gulp');
var proxyMiddleware = require('http-proxy-middleware');
var browserSync     = require('browser-sync').create();
var sass            = require('gulp-sass');

// Static Server + watching scss/html files
gulp.task('serve', ['sass'], function() {
    browserSync.init({
    	port: 9000,
        server: "./app"
    });

    gulp.watch("app/assets/*.scss", ['sass']);
    gulp.watch("app/*.html").on('change', browserSync.reload);
});

// Compile sass into CSS & auto-inject into browsers
gulp.task('sass', function() {
    return gulp.src("app/assets/*.scss")
        .pipe(sass())
        .pipe(gulp.dest("app/assets/"))
        .pipe(browserSync.stream());
});


// Static Server + watching css/html files
gulp.task('serve2', ['css'], function() {
    var proxy = proxyMiddleware('/context/api', {target: 'http://localhost:8080/context/api'});
    browserSync.init({
        server: {
            baseDir: ".",
            routes: { "/context": "app" },
            middleware: [ proxy ]
        },
        startPath: '/context'
    });

    gulp.watch("app/assets/*.css", ['css']);
    gulp.watch("app/*.html").on('change', browserSync.reload);
});

gulp.task('css', function() {
    return gulp.src("app/assets/*.css")
        .pipe(browserSync.stream());
});