#54 - add unit and integration tests for missing return statement analysis

Author: Stepami

tests/HydraScript.IntegrationTests/ErrorPrograms/FunctionWithoutReturnStatementTests.cs

@@ -0,0 +1,24 @@
+using HydraScript.Infrastructure;
+
+namespace HydraScript.IntegrationTests.ErrorPrograms;
+
+public class FunctionWithoutReturnStatementTests(TestHostFixture fixture) : IClassFixture<TestHostFixture>
+{
+    [Fact]
+    public void FunctionDeclaration_MissingReturn_HydraScriptError()
+    {
+        const string script =
+            """
+            function f(b: boolean) {
+                if (b)
+                    return 1
+            }
+            """;
+        using var runner = fixture.GetRunner(new TestHostFixture.Options(InMemoryScript: script));
+        var code = runner.Invoke();
+        code.Should().Be(Executor.ExitCodes.HydraScriptError);
+        fixture.LogMessages.Should()
+            .Contain(x =>
+                x.Contains("function with non-void return type must have a return statement"));
+    }
+}

tests/HydraScript.UnitTests/Application/ReturnAnalyzerTests.cs

@@ -0,0 +1,42 @@
+using HydraScript.Application.StaticAnalysis.Visitors;
+using HydraScript.Domain.FrontEnd.Parser.Impl.Ast.Nodes.Declarations;
+using HydraScript.Domain.FrontEnd.Parser.Impl.Ast.Nodes.Declarations.AfterTypesAreLoaded;
+using HydraScript.Domain.FrontEnd.Parser.Impl.Ast.Nodes.Expressions.PrimaryExpressions;
+using HydraScript.Domain.FrontEnd.Parser.Impl.Ast.Nodes.Statements;
+
+namespace HydraScript.UnitTests.Application;
+
+public class ReturnAnalyzerTests
+{
+    /// <summary>
+    /// <code>
+    /// function f(b: boolean) {
+    ///     if (b)
+    ///         return 1
+    /// }
+    /// </code>
+    /// </summary>
+    [Fact]
+    public void Visit_FunctionWithMissingReturn_CodePathEndedWithReturnIsFalse()
+    {
+        // Arrange
+        var functionDeclaration = new FunctionDeclaration(
+            new IdentifierReference("f"),
+            new TypeIdentValue(new IdentifierReference("undefined")),
+            [new NamedArgument("b", new TypeIdentValue(new IdentifierReference("boolean")))],
+            new BlockStatement([
+                new IfStatement(
+                    new IdentifierReference("b"),
+                    new ReturnStatement(
+                        new Literal(new TypeIdentValue(new IdentifierReference("number")), 1, "segment")))
+            ]));
+
+        // Act
+        var result = new ReturnAnalyzer().Visit(functionDeclaration);
+
+        // Assert
+        result.CodePathEndedWithReturn.Should().BeFalse();
+        result.ReturnStatements.Count.Should().Be(1);
+        result.ReturnStatements[0].Expression.Should().BeOfType<Literal>();
+    }
+}