(test) Minor test improvements

Extracted from changes originally done in
#409, to keep the git history
a bit more tidy.

release-notes/v0.3.0.md

@@ -3,6 +3,7 @@
 - The REPL is also noticeably nicer to use now, particularly for those of us used to bash/Emacs-like keybindings. [[#354][354]], [[#356][356]]
 - API docs on the website was broken since the v0.2.0 release for unknown reasons. [[#344][344]] has more details.
 - Based on community feedback, the project README was also slightly improved. [[#371][371]]
+- All changes below were made by @perlun
 
 ### Added
 #### Data types

release-notes/v0.4.0.md

@@ -1,5 +1,7 @@
 ## [0.4.0] - Unreleased
 - The fourth public release of Perlang.
+- For more details on how to install Perlang on your own machine, see https://perlang.org/download/.
+- All changes below were made by @perlun
 
 ### Added
 #### Experimental compilation
@@ -22,6 +24,9 @@
 
 ### Fixed
 
+### Tests
+- Minor test improvements [[#410][410]]
+
 [366]: https://github.com/perlang-org/perlang/pull/366
 [369]: https://github.com/perlang-org/perlang/pull/369
 [374]: https://github.com/perlang-org/perlang/pull/374
@@ -31,3 +36,4 @@
 [386]: https://github.com/perlang-org/perlang/pull/386
 [389]: https://github.com/perlang-org/perlang/pull/389
 [407]: https://github.com/perlang-org/perlang/pull/407
+[410]: https://github.com/perlang-org/perlang/pull/410

src/Perlang.Common/Expr.cs

@@ -344,7 +344,14 @@ public override string ToString() =>
 
         public class Get : Expr, ITokenAware
         {
+            /// <summary>
+            /// Gets the target object whose field/property/method is being accessed.
+            /// </summary>
             public Expr Object { get; }
+
+            /// <summary>
+            /// Gets the name of the field/property/method that is being accessed.
+            /// </summary>
             public Token Name { get; }
 
             // TODO: Would be much nicer to have this be without setter, but there is no easy way to accomplish this,

src/Perlang.Common/Stmt.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System.Collections.Generic;
 using System.Collections.Immutable;
 
@@ -99,9 +100,9 @@ public class If : Stmt
         {
             public Expr Condition { get; }
             public Stmt ThenBranch { get; }
-            public Stmt ElseBranch { get; }
+            public Stmt? ElseBranch { get; }
 
-            public If(Expr condition, Stmt thenBranch, Stmt elseBranch)
+            public If(Expr condition, Stmt thenBranch, Stmt? elseBranch)
             {
                 Condition = condition;
                 ThenBranch = thenBranch;
@@ -132,9 +133,9 @@ public override TR Accept<TR>(IVisitor<TR> visitor)
         public class Return : Stmt
         {
             public Token Keyword { get; }
-            public Expr Value { get; }
+            public Expr? Value { get; }
 
-            public Return(Token keyword, Expr value)
+            public Return(Token keyword, Expr? value)
             {
                 Keyword = keyword;
                 Value = value;

src/Perlang.Interpreter/PerlangInterpreter.cs

@@ -323,7 +323,7 @@ private void RegisterGlobalClasses()
                 // validation steps on the complete program now (all the statements executed up to now + the expression
                 // we just received).
                 var previousAndNewStatements = previousStatements
-                    .Concat(ImmutableList.Create(new Stmt.ExpressionStmt(result.Expr)))
+                    .Concat(ImmutableList.Create(new Stmt.ExpressionStmt(result.Expr!)))
                     .ToImmutableList();
 
                 //

src/Perlang.Interpreter/Typing/TypeValidator.cs

@@ -32,7 +32,7 @@ public static void Validate(
             bool typeResolvingFailed = false;
 
             //
-            // Phase 1: Resolve explicit and explicit type references to their corresponding CLR types.
+            // Phase 1: Resolve explicit and implicit type references to their corresponding CLR types.
             //
             var typeResolver = new TypeResolver(
                 getVariableOrFunctionCallback,

src/Perlang.Stdlib/Internal/Utils.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Globalization;
+using System.Numerics;
 using Perlang.Internal.Extensions;
 using Perlang.Lang;
 using String = Perlang.Lang.String;

src/Perlang.Tests.Integration/Comments/CommentsTests.cs

@@ -1,3 +1,4 @@
+using FluentAssertions;
 using Xunit;
 using static Perlang.Tests.Integration.EvalHelper;
 
@@ -27,19 +28,21 @@ public void only_line_comment()
         {
             string source = "// comment";
 
-            var output = Eval(source);
+            var output = EvalReturningOutputString(source);
 
-            Assert.Null(output);
+            output.Should()
+                .BeEmpty();
         }
 
         [Fact]
         public void only_line_comment_and_line()
         {
             string source = "// comment\n";
 
-            var output = Eval(source);
+            var output = EvalReturningOutputString(source);
 
-            Assert.Null(output);
+            output.Should()
+                .BeEmpty();
         }
 
         [Fact]

src/Perlang.Tests.Integration/For/Syntax.cs

@@ -1,3 +1,4 @@
+using FluentAssertions;
 using Xunit;
 using static Perlang.Tests.Integration.EvalHelper;
 
@@ -128,7 +129,10 @@ public void statement_bodies()
 
             var output = EvalReturningOutput(source);
 
-            Assert.Equal(new string[] { }, output);
+            // TODO: Nothing is expected to have been printed by the above, but perhaps we could make this test better
+            // TODO: and print in the branches?
+            output.Should()
+                .BeEmpty();
         }
     }
 }

src/Perlang.Tests.Integration/Function/Return.cs

@@ -12,6 +12,9 @@ public void function_can_return_values_in_if_statement()
                 fun f(i: int): int {
                     if (i < 10) return i;
                     if (i >= 10) return i / 2;
+
+                    // Will never be reached
+                    return -1;
                 }
 
                 print f(5);

src/Perlang.Tests.Integration/LogicalOperator/AmbiguousCombinationOfOperators.cs

@@ -1,4 +1,5 @@
 using System.Linq;
+using FluentAssertions;
 using Xunit;
 using static Perlang.Tests.Integration.EvalHelper;
 
@@ -61,7 +62,8 @@ public void grouped_and_and_or_operators_does_not_emit_warnings()
 
             string output = EvalReturningOutput(source).SingleOrDefault();
 
-            Assert.Equal("False", output);
+            output!.Should()
+                .Be("False");
         }
     }
 }

src/Perlang.Tests.Integration/LogicalOperator/And.cs

@@ -1,4 +1,5 @@
 using System.Linq;
+using FluentAssertions;
 using Xunit;
 using static Perlang.Tests.Integration.EvalHelper;
 
@@ -47,7 +48,8 @@ public void true_is_truthy()
 
             string output = EvalReturningOutput(source).SingleOrDefault();
 
-            Assert.Equal("True", output);
+            output!.Should()
+                .Be("True");
         }
 
         [Fact]
@@ -61,7 +63,8 @@ public void false_is_falsy()
 
             string output = EvalReturningOutput(source).SingleOrDefault();
 
-            Assert.Equal("False", output);
+            output!.Should()
+                .Be("False");
         }
 
         [Fact]

src/Perlang.Tests.Integration/LogicalOperator/Or.cs

@@ -1,4 +1,5 @@
 using System.Linq;
+using FluentAssertions;
 using Xunit;
 using static Perlang.Tests.Integration.EvalHelper;
 
@@ -47,7 +48,8 @@ public void true_is_truthy()
 
             string output = EvalReturningOutput(source).SingleOrDefault();
 
-            Assert.Equal("True", output);
+            output!.Should()
+                .Be("True");
         }
 
         [Fact]
@@ -61,7 +63,8 @@ public void false_is_falsy()
 
             string output = EvalReturningOutput(source).SingleOrDefault();
 
-            Assert.Equal("False", output);
+            output!.Should()
+                .Be("False");
         }
 
         [Fact]

src/Perlang.Tests.Integration/Operator/Binary/BinaryOperatorDataTests.cs

@@ -172,8 +172,8 @@ void Exponential_has_test_data_for_all_supported_primitive_types()
         EnsureAllPrimitiveTypesAreHandled(Exponential_result, Exponential_unsupported_types, "Exponential");
     }
 
-    // EnsureAllPrimitiveTypePairsAreHandled deliberately not tests for the exponential operator, since it only supports
-    // a limited subset of operand types.
+    // EnsureAllPrimitiveTypePairsAreHandled deliberately does not test for the exponential operator, since it only
+    // supports a limited subset of operand types.
 
     [Fact]
     void Modulo_has_test_data_for_all_supported_primitive_types()