src/test/java/org/zwobble/couscous/tests/JavaToPythonTests.java


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64

package org.zwobble.couscous.tests;

import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

import org.junit.Test;
import org.zwobble.couscous.ast.ClassNode;
import org.zwobble.couscous.ast.TypeName;
import org.zwobble.couscous.frontends.java.JavaFrontend;
import org.zwobble.couscous.tests.backends.python.PythonMethodRunner;
import org.zwobble.couscous.values.PrimitiveValue;

import static java.util.Arrays.asList;
import static org.junit.Assert.assertEquals;
import static org.zwobble.couscous.tests.util.ExtraFiles.deleteRecursively;
import static org.zwobble.couscous.values.PrimitiveValues.value;

public class JavaToPythonTests {
    @Test
    public void canEvaluateLiterals() {
        assertEquals(value("hello"), evalExpression("\"hello\""));
        assertEquals(value(42), evalExpression("42"));
    }
    
    @Test
    public void canUseOperatorsOnPrimitives() {
        assertEquals(value(3), evalExpression("1 + 2"));
        assertEquals(value(false), evalExpression("1 > 2"));
        assertEquals(value(true), evalExpression("1 == 1"));
        assertEquals(value(false), evalExpression("1 != 1"));
    }
    
    @Test
    public void equalityOnReferenceTypesChecksForIdentity() {
        assertEquals(value(false), evalExpression("new Object() == new Object()"));
        assertEquals(value(true), exec("Object x = new Object(); return x == x;"));
    }
    
    private PrimitiveValue exec(String source) {
        try {
            String javaClass =
                "package com.example;" +
                "public class Example {" +
                "    public static Object main() {" + source + "}" +
                "}";
            Path directoryPath = Files.createTempDirectory(null);
            try {
                Files.createDirectories(directoryPath.resolve("com/example"));
                Files.write(directoryPath.resolve("com/example/Example.java"), asList(javaClass));
                List<ClassNode> classNodes = JavaFrontend.readSourceDirectory(directoryPath);
                return new PythonMethodRunner().runMethod(classNodes, TypeName.of("com.example.Example"), "main", asList());
            } finally {
                deleteRecursively(directoryPath.toFile());
            }
        } catch (final java.lang.Throwable $ex) {
            throw new RuntimeException($ex);
        }
    }
    
    private PrimitiveValue evalExpression(String expressionSource) {
        return exec("return " + expressionSource + ";");
    }
}