Type check native function declarations

3 files changed, 135 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/ast/typed/TypedNativeFunctionDeclarationNodeMatcher.java b/src/test/java/org/shedlang/compiler/ast/typed/TypedNativeFunctionDeclarationNodeMatcher.java
new file mode 100644
index 00000000..94c8c65a
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/ast/typed/TypedNativeFunctionDeclarationNodeMatcher.java
@@ -0,0 +1,59 @@
+package org.shedlang.compiler.ast.typed;
+
+import org.pcollections.Empty;
+import org.pcollections.PVector;
+import org.shedlang.compiler.testing.MatcherBuilder;
+import org.shedlang.compiler.types.FunctionType;
+import org.zwobble.precisely.Matcher;
+
+import java.util.Optional;
+
+import static org.zwobble.precisely.Matchers.*;
+
+public class TypedNativeFunctionDeclarationNodeMatcher extends MatcherBuilder<
+    TypedNamespaceStatementNode,
+    TypedNativeFunctionDeclarationNode,
+    TypedNativeFunctionDeclarationNodeMatcher
+> {
+    public static TypedNativeFunctionDeclarationNodeMatcher empty() {
+        return new TypedNativeFunctionDeclarationNodeMatcher(Empty.vector());
+    }
+
+    public TypedNativeFunctionDeclarationNodeMatcher(
+        PVector<Matcher<? super TypedNativeFunctionDeclarationNode>> submatchers
+    ) {
+        super(submatchers);
+    }
+
+    @Override
+    protected Class<TypedNativeFunctionDeclarationNode> expectedType() {
+        return TypedNativeFunctionDeclarationNode.class;
+    }
+
+    @Override
+    protected TypedNativeFunctionDeclarationNodeMatcher create(
+        PVector<Matcher<? super TypedNativeFunctionDeclarationNode>> submatchers
+    ) {
+        return new TypedNativeFunctionDeclarationNodeMatcher(submatchers);
+    }
+
+    public TypedNativeFunctionDeclarationNodeMatcher withEffect(Matcher<Optional<? extends TypedTypeLevelExpressionNode<?>>> effect) {
+        return with(has("effect", x -> x.signature().effect(), effect));
+    }
+
+    public TypedNativeFunctionDeclarationNodeMatcher withName(String name) {
+        return with(has("name", x -> x.name(), equalTo(name)));
+    }
+
+    public TypedNativeFunctionDeclarationNodeMatcher withParams(Matcher<TypedParamsNode> params) {
+        return with(has("params", x -> x.signature().params(), params));
+    }
+
+    public TypedNativeFunctionDeclarationNodeMatcher withReturnType(Matcher<TypedTypeLevelExpressionNode<?>> returnType) {
+        return with(has("returnType", x -> x.signature().returnType(), isOptionalOf(returnType)));
+    }
+
+    public TypedNativeFunctionDeclarationNodeMatcher withType(FunctionType type) {
+        return with(has("type", x -> x.type(), equalTo(type)));
+    }
+}
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 2002577f..902ba59d 100644
--- a/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java
@@ -244,6 +244,10 @@ public class TypedNodeMatchers {
         return TypedNamespaceNodeMatcher.empty();
     }
 
+    public static TypedNativeFunctionDeclarationNodeMatcher isTypedNativeFunctionDeclarationNode() {
+        return TypedNativeFunctionDeclarationNodeMatcher.empty();
+    }
+
     public static Matcher<TypedParamNode> isTypedParamNode(
         String name,
         Matcher<Optional<? extends TypedTypeLevelExpressionNode<?>>> type
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerNativeFunctionDeclarationTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerNativeFunctionDeclarationTests.java
new file mode 100644
index 00000000..b6a5ce9d
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerNativeFunctionDeclarationTests.java
@@ -0,0 +1,72 @@
+package org.shedlang.compiler.typechecker;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.ast.untyped.Untyped;
+import org.shedlang.compiler.ast.untyped.UntypedNativeFunctionDeclarationNode;
+import org.shedlang.compiler.typechecker.errors.FunctionSignatureMissingParamTypeError;
+import org.shedlang.compiler.typechecker.errors.FunctionSignatureMissingReturnTypeError;
+import org.shedlang.compiler.types.FunctionType;
+import org.shedlang.compiler.types.Types;
+import org.shedlang.compiler.util.P;
+
+import java.util.Map;
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.shedlang.compiler.ast.typed.TypedNodeMatchers.*;
+import static org.shedlang.compiler.typechecker.TypeCheckerTesting.typeCheckNamespaceStatement;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.isOptionalEmpty;
+import static org.zwobble.precisely.Matchers.isSequence;
+
+public class TypeCheckerNativeFunctionDeclarationTests {
+    @Test
+    public void canTypeCheckMinimalNativeFunctionDeclaration() {
+        var untyped = UntypedNativeFunctionDeclarationNode.builder()
+            .withName("f")
+            .withReturnType(Untyped.typeLevelReference("Unit"))
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .enterGlobal(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
+
+        var typed = typeCheckNamespaceStatement(untyped, context);
+
+        assertThat(
+            typed.value(),
+            isTypedNativeFunctionDeclarationNode()
+                .withName("f")
+                .withParams(isTypedParamsNode(isSequence(), isSequence()))
+                .withEffect(isOptionalEmpty())
+                .withReturnType(isTypedTypeLevelReferenceNode("Unit", Types.UNIT))
+                .withType(FunctionType.builder().withReturnType(Types.UNIT).build())
+        );
+    }
+
+    @Test
+    public void whenSignatureIsMissingReturnTypeThenErrorIsThrown() {
+        var untyped = UntypedNativeFunctionDeclarationNode.builder()
+            .withoutReturnType()
+            .build();
+        var context = TypeCheckerContext.EMPTY;
+
+        assertThrows(
+            FunctionSignatureMissingReturnTypeError.class,
+            () -> typeCheckNamespaceStatement(untyped, context)
+        );
+    }
+
+    @Test
+    public void whenSignatureIsMissingParamTypeThenErrorIsThrown() {
+        var untyped = UntypedNativeFunctionDeclarationNode.builder()
+            .addPositionalParam("x", Optional.empty())
+            .withReturnType(Untyped.typeLevelReference("Unit"))
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .enterGlobal(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
+
+        assertThrows(
+            FunctionSignatureMissingParamTypeError.class,
+            () -> typeCheckNamespaceStatement(untyped, context)
+        );
+    }
+}