Type check break statements

4 files changed, 80 insertions, 2 deletions

diff --git a/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java b/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java
index bb787024..0014e4f0 100644
--- a/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java
@@ -68,6 +68,15 @@ public class TypedNodeMatchers {
         );
     }
 
+    public static Matcher<TypedFunctionStatementNode> isTypedBreakNode(
+        Matcher<TypedExpressionNode> expression
+    ) {
+        return instanceOf(
+            TypedBreakNode.class,
+            has("expression", x -> x.expression(), expression)
+        );
+    }
+
     public static TypedCallNodeMatcher isTypedCallNode() {
         return TypedCallNodeMatcher.empty();
     }
diff --git a/src/test/java/org/shedlang/compiler/ast/untyped/Untyped.java b/src/test/java/org/shedlang/compiler/ast/untyped/Untyped.java
index 51b6c2b6..8d105dd9 100644
--- a/src/test/java/org/shedlang/compiler/ast/untyped/Untyped.java
+++ b/src/test/java/org/shedlang/compiler/ast/untyped/Untyped.java
@@ -43,6 +43,14 @@ public class Untyped {
         return new UntypedBoolLiteralNode(value, Sources.NULL);
     }
 
+    public static UntypedBreakNode break_() {
+        return new UntypedBreakNode(Optional.empty(), Sources.NULL);
+    }
+
+    public static UntypedBreakNode break_(UntypedExpressionNode expression) {
+        return new UntypedBreakNode(Optional.of(expression), Sources.NULL);
+    }
+
     public static UntypedCallNode call(
         UntypedExpressionNode receiver,
         List<UntypedExpressionNode> positionalArgs
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerBreakTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerBreakTests.java
new file mode 100644
index 00000000..32f7b127
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerBreakTests.java
@@ -0,0 +1,61 @@
+package org.shedlang.compiler.typechecker;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.ast.untyped.Untyped;
+import org.shedlang.compiler.typechecker.errors.CannotBreakOutsideOfEffectHandlerMethodError;
+import org.shedlang.compiler.types.Effects;
+import org.shedlang.compiler.types.NamespaceName;
+import org.shedlang.compiler.types.Types;
+import org.shedlang.compiler.util.P;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.shedlang.compiler.ast.typed.TypedNodeMatchers.*;
+import static org.zwobble.precisely.AssertThat.assertThat;
+
+public class TypeCheckerBreakTests {
+    @Test
+    public void expressionIsTypeChecked() {
+        var untyped = Untyped.break_(Untyped.stringLiteral("hello"));
+        var context = TypeCheckerContext.EMPTY
+            .enterFunction(P.map(), Effects.NONE, ReturnTypeState.effectHandler(Types.INT));
+
+        var typed = TypeChecker.typeCheckFunctionStatement(untyped, context);
+
+        assertThat(typed.value(), isTypedBreakNode(isTypedStringLiteralNode("hello")));
+    }
+
+    @Test
+    public void whenExpressionIsAbsentThenUnitIsReturned() {
+        var untyped = Untyped.break_();
+        var context = TypeCheckerContext.EMPTY
+            .enterFunction(P.map(), Effects.NONE, ReturnTypeState.effectHandler(Types.UNIT));
+
+        var typed = TypeChecker.typeCheckFunctionStatement(untyped, context);
+
+        assertThat(typed.value(), isTypedBreakNode(isTypedUnitLiteralNode()));
+    }
+
+    @Test
+    public void whenInNamespaceThenResumeIsForbidden() {
+        var untyped = Untyped.break_(Untyped.stringLiteral("hello"));
+        var context = TypeCheckerContext.EMPTY
+            .enterNamespace(NamespaceName.of("Example"), P.map());
+
+        assertThrows(
+            CannotBreakOutsideOfEffectHandlerMethodError.class,
+            () -> TypeChecker.typeCheckFunctionStatement(untyped, context)
+        );
+    }
+
+    @Test
+    public void whenInFunctionThenResumeIsForbidden() {
+        var untyped = Untyped.break_(Untyped.stringLiteral("hello"));
+        var context = TypeCheckerContext.EMPTY
+            .enterFunction(P.map(), Effects.NONE, ReturnTypeState.explicit(Types.STRING));
+
+        assertThrows(
+            CannotBreakOutsideOfEffectHandlerMethodError.class,
+            () -> TypeChecker.typeCheckFunctionStatement(untyped, context)
+        );
+    }
+}
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerResumeTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerResumeTests.java
index f0f18839..b5bab880 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerResumeTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerResumeTests.java
@@ -43,7 +43,7 @@ public class TypeCheckerResumeTests {
     }
 
     @Test
-    public void whenNotInFunctionThenResumeIsForbidden() {
+    public void whenInNamespaceThenResumeIsForbidden() {
         var untyped = Untyped.resume(Untyped.stringLiteral("hello"));
         var context = TypeCheckerContext.EMPTY
             .enterNamespace(NamespaceName.of("Example"), P.map());
@@ -67,7 +67,7 @@ public class TypeCheckerResumeTests {
     }
 
     @Test
-    public void canResumeWIthSubtypeOfResumeType() {
+    public void canResumeWithSubtypeOfResumeType() {
         var untyped = Untyped.resume(Untyped.stringLiteral("hello"));
         var context = TypeCheckerContext.EMPTY
             .enterFunction(P.map(), Effects.NONE, ReturnTypeState.effectHandler(Types.TOP));