jsexpr/test/test001.js

String and JSON expression interpolator and evaluator. Interpolates or evaluates a string against a json object, or transforms an object into another based on a json template

const
	expression = require("../"),
	assert = require('assert');

const MODES = ["eval","iteval","ceval"];

MODES.forEach(mode=>{
	describe(`Expression parser (${mode})`, function() {
		it('Should parse expression', function() {
			try {
				let fn1 = expression.fn('(${a} + ${b}) / ${c} + ${d.e}',mode);
				assert.ok("Expression parsed");
			}catch(err) {
				assert.fail("Error thrown");
			}
		});

		it('Should throw error', function() {
			try {
				var error = null;
				let fn2 = expression.fn('(${a} < ${d.e}',mode);
			}catch(err) {
				error = err;
			}
			assert(error!=null);
		});
	});

	describe(`String evaluation (${mode})`, function() {
		let fn1 = expression.fn('(${a} + ${b}) / ${c} + ${d.e}',mode);
		let fn2 = expression.fn('(${a[1]} + ${b[2]}) / ${c[this.d.e]}',mode);
		let fn3 = expression.fn('${a} < ${d.e}',mode);
		let fn4 = expression.fn('${$a} < ${$d.e}',mode);

		it('Should perform operation', function() {
			let res = fn1({a:5,b:10,c:3,d:{e:30}});
			assert.equal(35,res);
		});
		it('Should perform operation with missing value', function() {
			let res = fn1({b:10,c:2,d:{e:30}});
			assert.equal(35,res);
		});
		if(mode!='iteval') {
			it('Should perform operation with arrays and `this`', function() {
				let res = fn2({a:[1,5],b:[2,5,10,20],c:[4,3,4],d:{e:1}});
				assert.equal(5,res);
			});
		}
		it('Should fail operation with missing values', function() {
			let res = fn1({d:{e:30}});
			assert(isNaN(res));
		});
		it('Should evaluate condition (true)', function() {
			let res = fn3({a:5,d:{e:30}});
			assert.equal(true,res);
		});
		it('Should evaluate condition (false)', function() {
			let res = fn3({a:30,d:{e:30}});
			assert.equal(false,res);
		});
		it('Should evaluate condition with $ (true)', function() {
			let res = fn4({$a:5,$d:{e:30}});
			assert.equal(true,res);
		});
	});

	describe(`String interpolation (${mode})`, function() {
		debugger;
		let fn1 = expression.expr('(${a} + ${b}) / ${c} + ${d.e}',mode);
		let fn2 = expression.expr('${a} < ${d.e}',mode);
		let fn3 = expression.expr('${$a} < ${$d.e}',mode);

		it('Should interpolate operation', function() {
			let res = fn1({a:5,b:10,c:3,d:{e:30}});
			assert.equal('(5 + 10) / 3 + 30',res);
		});
		it('Should interpolate operation', function() {
			let res = fn3({$a:5,b:10,c:3,$d:{e:30}});
			assert.equal('5 < 30',res);
		});
		it('Should interpolate with missing values', function() {
			let res = fn1({b:10,c:2,d:{e:30}});
			assert.equal('( + 10) / 2 + 30',res);
		});
	});
});