jest setup

src/Interp.js

@@ -1,17 +1,16 @@
 /*
- Welcome to the interpreter!
- It only supports the following expressions and statements:
- - numbers
- - booleans
- - variables
- - if statements
- - function expression
- - function calls
- - +, -, *, /
-*/
+ * Welcome to the interpreter!
+
+ * It only supports the following expressions and statements:
+ * - numbers
+ * - booleans
+ * - variables
+ * - if statements
+ * - function expression
+ * - function calls
+ * - `+`, `-`, `*`, `/`
+ */
 
-import { parse } from './Parser';
-import { readFile } from './Reader';
 import {
  emptyEnv,
  lookupEnv,
@@ -23,9 +22,6 @@ import {
  applyClosure,
 } from './Closure';
 
-const code = readFile('../samples/adder.js');
-const ast = parse(code);
-
 const expInterp = (exp, env) => {
  switch (exp.type) {
  case 'ArrowFunctionExpression': {
@@ -50,6 +46,10 @@ const expInterp = (exp, env) => {
  const { value: val } = exp;
  return { val, env };
  }
+ case 'BooleanLiteral': {
+ const { value: val } = exp;
+ return { val, env };
+ }
  case 'Identifier': {
  const { name } = exp;
  const val = lookupEnv(name, env);
@@ -106,7 +106,7 @@ const blockStatementInterp = (exp, env) => {
  }
 };
 
-const programInterp = (exp, env) => {
+const programInterp = (exp, env = emptyEnv) => {
  switch (exp.type) {
  case 'Program': {
  const { val } = exp.body.reduce(
@@ -121,4 +121,4 @@ const programInterp = (exp, env) => {
  }
 };
 
-console.log(programInterp(ast, emptyEnv));
+export { programInterp };

src/__tests__/Environment-test.js

@@ -1,4 +1,4 @@
-jest.unmock('../Environment').unmock('immutable');
+jest.disableAutomock();
 
 const {
  emptyEnv,

src/__tests__/Interp-test.js

@@ -0,0 +1,18 @@
+jest.disableAutomock();
+
+const { programInterp } = require('../Interp');
+const { parse } = require('../Parser');
+
+const parseAndEval = (code) => programInterp(parse(code));
+
+describe('Interp', () => {
+ it('should support trivial prim types', () => {
+ expect(parseAndEval('3;')).toBe(3);
+ expect(parseAndEval('true;')).toBe(true);
+ });
+
+ it('should support arrow function expressions', () => {
+ expect(parseAndEval('const foo = (x, y) => 3; foo(100, 200)')).toBe(3);
+ expect(parseAndEval('const foo = (x) => (y) => x + y; foo(12)(24)')).toBe(36);
+ });
+});