Split switch handling off to desugar step

1 files changed, 129 insertions, 0 deletions

diff --git a/src/test/java/org/zwobble/couscous/tests/transforms/DesugarSwitchToIfElseTests.java b/src/test/java/org/zwobble/couscous/tests/transforms/DesugarSwitchToIfElseTests.java
new file mode 100644
index 0000000..9e458e7
--- /dev/null
+++ b/src/test/java/org/zwobble/couscous/tests/transforms/DesugarSwitchToIfElseTests.java
@@ -0,0 +1,129 @@
+package org.zwobble.couscous.tests.transforms;
+
+import org.junit.Test;
+import org.zwobble.couscous.ast.Operations;
+import org.zwobble.couscous.ast.VariableDeclaration;
+import org.zwobble.couscous.ast.identifiers.Identifiers;
+import org.zwobble.couscous.ast.sugar.SwitchNode;
+import org.zwobble.couscous.frontends.java.Scope;
+import org.zwobble.couscous.transforms.DesugarSwitchToIfElse;
+import org.zwobble.couscous.types.Types;
+
+import static org.junit.Assert.assertEquals;
+import static org.zwobble.couscous.ast.ExpressionStatementNode.expressionStatement;
+import static org.zwobble.couscous.ast.IfStatementNode.ifStatement;
+import static org.zwobble.couscous.ast.LiteralNode.literal;
+import static org.zwobble.couscous.ast.LocalVariableDeclarationNode.localVariableDeclaration;
+import static org.zwobble.couscous.ast.ReturnNode.returns;
+import static org.zwobble.couscous.ast.VariableDeclaration.var;
+import static org.zwobble.couscous.ast.VariableReferenceNode.reference;
+import static org.zwobble.couscous.ast.sugar.SwitchCaseNode.switchCase;
+import static org.zwobble.couscous.util.ExtraLists.list;
+
+public class DesugarSwitchToIfElseTests {
+    @Test
+    public void switchStatementWithoutFallThroughIsReadAsIfElseStatement() {
+        VariableDeclaration tmp = var(
+            Identifiers.variable(Identifiers.TOP, "_couscous_tmp_0"),
+            "_couscous_tmp_0",
+            Types.STRING
+        );
+        assertEquals(
+            list(
+                localVariableDeclaration(tmp, literal("one")),
+                ifStatement(
+                    Operations.methodEquals(reference(tmp), literal("one")),
+                    list(returns(literal(1))),
+                    list(
+                        ifStatement(
+                            Operations.methodEquals(reference(tmp), literal("two")),
+                            list(returns(literal(2))),
+                            list(
+                                returns(literal(0))
+                            )
+                        )
+                    )
+                )
+            ),
+            DesugarSwitchToIfElse.desugar(
+                Scope.create(),
+                new SwitchNode(
+                    literal("one"),
+                    list(
+                        switchCase(literal("one"), list(returns(literal(1)))),
+                        switchCase(literal("two"), list(returns(literal(2)))),
+                        switchCase(list(returns(literal(0))))
+                    )
+                )
+            )
+        );
+    }
+
+    @Test
+    public void switchStatementWithoutDefaultIsReadAsIfStatementWithoutElseStatement() {
+        VariableDeclaration tmp = var(
+            Identifiers.variable(Identifiers.TOP, "_couscous_tmp_0"),
+            "_couscous_tmp_0",
+            Types.STRING
+        );
+        assertEquals(
+            list(
+                localVariableDeclaration(tmp, literal("one")),
+                ifStatement(
+                    Operations.methodEquals(reference(tmp), literal("two")),
+                    list(returns(literal(0))),
+                    list()
+                )
+            ),
+            DesugarSwitchToIfElse.desugar(
+                Scope.create(),
+                new SwitchNode(
+                    literal("one"),
+                    list(
+                        switchCase(literal("two"), list(returns(literal(0))))
+                    )
+                )
+            )
+        );
+    }
+
+    @Test
+    public void casesCanFallthrough() {
+        VariableDeclaration tmp = var(
+            Identifiers.variable(Identifiers.TOP, "_couscous_tmp_0"),
+            "_couscous_tmp_0",
+            Types.STRING
+        );
+        assertEquals(
+            list(
+                localVariableDeclaration(tmp, literal("one")),
+                ifStatement(
+                    Operations.methodEquals(reference(tmp), literal("one")),
+                    list(
+                        expressionStatement(literal(1)),
+                        returns(literal(2))
+                    ),
+                    list(
+                        ifStatement(
+                            Operations.methodEquals(reference(tmp), literal("two")),
+                            list(
+                                returns(literal(2))
+                            ),
+                            list()
+                        )
+                    )
+                )
+            ),
+            DesugarSwitchToIfElse.desugar(
+                Scope.create(),
+                new SwitchNode(
+                    literal("one"),
+                    list(
+                        switchCase(literal("one"), list(expressionStatement(literal(1)))),
+                        switchCase(literal("two"), list(returns(literal(2))))
+                    )
+                )
+            )
+        );
+    }
+}