add unit tests for Evaller class

test/EvallerTest.php

@@ -0,0 +1,211 @@
+<?php
+/**
+ * MadLisp language
+ * @link http://madlisp.com/
+ * @copyright Copyright (c) 2020 Pekka Laiho
+ */
+
+use PHPUnit\Framework\TestCase;
+
+use MadLisp\Env;
+use MadLisp\Evaller;
+use MadLisp\Hash;
+use MadLisp\MadLispException;
+use MadLisp\MList;
+use MadLisp\Printer;
+use MadLisp\Reader;
+use MadLisp\Symbol;
+use MadLisp\Tokenizer;
+use MadLisp\Vector;
+use MadLisp\Lib\Math;
+
+class EvallerTest extends TestCase
+{
+    public function testEvalAtom()
+    {
+        // Test values that are not evaluated (they are returned unchanged)
+
+        $env = $this->getEnv();
+        $evaller = $this->getEvaller();
+
+        $this->assertSame(true, $evaller->eval(true, $env));
+        $this->assertSame(false, $evaller->eval(false, $env));
+        $this->assertSame(null, $evaller->eval(null, $env));
+        $this->assertSame(123, $evaller->eval(123, $env));
+        $this->assertSame(4.56, $evaller->eval(4.56, $env));
+        $this->assertSame("abc", $evaller->eval("abc", $env));
+
+        $obj = new \stdClass();
+        $this->assertSame($obj, $evaller->eval($obj, $env));
+
+        $fn = fn ($a) => $a;
+        $this->assertSame($fn, $evaller->eval($fn, $env));
+
+        $fn = $env->get('+');
+        $this->assertSame($fn, $evaller->eval($fn, $env));
+    }
+
+    public function testEvalSymbol()
+    {
+        // Evaluating a symbol is a lookup from env
+
+        $env = $this->getEnv();
+        $env->set('abc', 123);
+        $env->set('efg', new MList([1, 2, 3]));
+
+        $evaller = $this->getEvaller();
+
+        $result = $evaller->eval(new Symbol('abc'), $env);
+        $this->assertSame(123, $result);
+
+        $result = $evaller->eval(new Symbol('efg'), $env);
+        $this->assertInstanceOf(MList::class, $result);
+        $this->assertSame([1, 2, 3], $result->getData());
+    }
+
+    public function testEvalSymbolNotFound()
+    {
+        // Evaluating a symbol that is not defined will throw an exception
+
+        $this->expectException(MadLispException::class);
+        $this->expectExceptionMessage('symbol abc not defined in env');
+
+        $env = $this->getEnv();
+        $evaller = $this->getEvaller();
+        $evaller->eval(new Symbol('abc'), $env);
+    }
+
+    public function testEvalEmptyList()
+    {
+        // Empty list is not changed
+
+        $env = $this->getEnv();
+        $evaller = $this->getEvaller();
+        $result = $evaller->eval(new MList(), $env);
+
+        $this->assertInstanceOf(MList::class, $result);
+        $this->assertCount(0, $result->getData());
+    }
+
+    public function testEvalVector()
+    {
+        // Evaluating a vector returns new vector where each element is evaluated
+
+        $env = $this->getEnv();
+        $evaller = $this->getEvaller();
+
+        $input = new Vector([
+            1,
+            2,
+            new MList([new Symbol('+'), 1, 2]),
+            new Vector([
+                4,
+                5,
+                new MList([new Symbol('+'), 2, 4])
+            ])
+        ]);
+
+        $result = $evaller->eval($input, $env);
+
+        $this->assertInstanceOf(Vector::class, $result);
+        $data = $result->getData();
+        $this->assertCount(4, $data);
+        $this->assertSame(1, $data[0]);
+        $this->assertSame(2, $data[1]);
+        $this->assertSame(3, $data[2]);
+
+        $this->assertInstanceOf(Vector::class, $data[3]);
+        $data2 = $data[3]->getData();
+        $this->assertCount(3, $data2);
+        $this->assertSame(4, $data2[0]);
+        $this->assertSame(5, $data2[1]);
+        $this->assertSame(6, $data2[2]);
+    }
+
+    public function testEvalHash()
+    {
+        // Evaluating a hash-map returns a new hash-map where the values are evaluated
+
+        $env = $this->getEnv();
+        $evaller = $this->getEvaller();
+
+        $input = new Hash([
+            "aa" => new MList([new Symbol('+'), 1, 2]),
+            "bb" => new Hash([
+                "cc" => new MList([new Symbol('+'), 3, 4])
+            ])
+        ]);
+
+        $result = $evaller->eval($input, $env);
+
+        $this->assertInstanceOf(Hash::class, $result);
+        $data = $result->getData();
+        $this->assertCount(2, $data);
+        $this->assertSame(3, $data['aa']);
+
+        $this->assertInstanceOf(Hash::class, $data['bb']);
+        $data2 = $data['bb']->getData();
+        $this->assertCount(1, $data2);
+        $this->assertSame(7, $data2['cc']);
+    }
+
+    public function testEvalList()
+    {
+        // Test simple list evaluation
+
+        $env = $this->getEnv();
+        $evaller = $this->getEvaller();
+
+        $input = new MList([
+            new Symbol('+'),
+            1,
+            2,
+            new MList([
+                new Symbol('*'),
+                4,
+                5
+            ])
+        ]);
+
+        $result = $evaller->eval($input, $env);
+
+        $this->assertSame(23, $result);
+    }
+
+    public function testEvalListNotFunc()
+    {
+        // Test that exception is thrown when evaluating a list
+        // where the first item is not a function.
+
+        $this->expectException(MadLispException::class);
+        $this->expectExceptionMessage('eval: first item of list is not function');
+
+        $env = $this->getEnv();
+        $evaller = $this->getEvaller();
+
+        $input = new MList([1, 2, 3]);
+
+        $evaller->eval($input, $env);
+    }
+
+    private function getEnv(): Env
+    {
+        $env = new Env('env');
+
+        // Define some math functions for testing
+        $lib = new Math();
+        $lib->register($env);
+
+        return $env;
+    }
+
+    private function getEvaller(): Evaller
+    {
+        return new Evaller(
+            new Tokenizer(),
+            new Reader(),
+            new Printer(),
+            false
+        );
+    }
+}