Fix tests

Author: danvim

lib/lisp.test.js

@@ -15,6 +15,9 @@ import {
 import { L } from './helper.js'
 import { UnboundVariableError } from './errors.js'
 
+const x = Symbol('x')
+const y = Symbol('y')
+
 describe('apply', () => {
   describe('CAR', () => {
     test('returns the head elements when present', () => {
@@ -72,7 +75,8 @@ describe('apply', () => {
 
   describe('function is unknown atom', () => {
     test('function value is evaluated from context and then applies to arguments', () => {
-      assert.strictEqual(lApply('atomAlias', L(NIL), L(['atomAlias', ATOM])), T)
+      const mySymbol = Symbol('mySymbol')
+      assert.strictEqual(lApply(mySymbol, L(NIL), L([mySymbol, ATOM])), T)
     })
     test('function that does not exist in context should throw exception', () => {
       assert.throws(() => lApply('unknownSymbol', L(), L()))
@@ -81,23 +85,19 @@ describe('apply', () => {
 
   describe('lambda', () => {
     test('returns evaluation result from lambda expression binding argument to parameter symbol', () => {
-      assert.strictEqual(lApply(L(LAMBDA, L('x'), 'x'), L(12)), 12)
+      assert.strictEqual(lApply(L(LAMBDA, L(x), x), L(12)), 12)
     })
 
     test('multiple parameter bindings and function call expressions are evaluated', () => {
       assert.deepStrictEqual(
-        lApply(L(LAMBDA, L('x', 'y'), L(CONS, 'x', 'y')), L(1, 2)),
+        lApply(L(LAMBDA, L(x, y), L(CONS, x, y)), L(1, 2)),
         [1, 2],
       )
     })
 
     test('parameter bound variable value should shadow variable value in context', () => {
       assert.strictEqual(
-        lApply(
-          L(LAMBDA, L('x'), 'x'),
-          L('localValue'),
-          L(['x', 'shadowedValue']),
-        ),
+        lApply(L(LAMBDA, L(x), x), L('localValue'), L([x, 'shadowedValue'])),
         'localValue',
       )
     })
@@ -107,10 +107,10 @@ describe('apply', () => {
 describe('eval', () => {
   describe('binding', () => {
     test('should return bound argument', () => {
-      assert.strictEqual(lEval('x', L(['x', 1])), 1)
+      assert.strictEqual(lEval(x, L([x, 1])), 1)
     })
     test('should throw if symbol not found', () => {
-      assert.throws(() => lEval('x', L()), UnboundVariableError)
+      assert.throws(() => lEval(x, L()), UnboundVariableError)
     })
   })
 })