Merge branch 'main' of github.com:ratfactor/ziglings

5 files changed, 213 insertions, 140 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ab821c6..d071d8f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,21 +27,21 @@ jobs:
       - name: Check compatibility with old Zig compilers
         run: ci/compat.sh
 
-#  test:
-#    name: Unit Tests
-#    strategy:
-#      matrix:
-#        os: [ubuntu-latest, windows-latest, macos-latest]
-#    runs-on: ${{ matrix.os }}
-#    timeout-minutes: 30
-#    steps:
-#      - name: Checkout
-#        uses: actions/checkout@v3
-#
-#      - name: Setup Zig
-#        uses: goto-bus-stop/setup-zig@v2
-#        with:
-#          version: master
-#
-#      - name: Run unit tests
-#        run: zig build test
+  test:
+    name: Unit Tests
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 30
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Setup Zig
+        uses: goto-bus-stop/setup-zig@v2
+        with:
+          version: master
+
+      - name: Run unit tests
+        run: zig build test
diff --git a/build.zig b/build.zig
index 1b4855d..64968b9 100644
--- a/build.zig
+++ b/build.zig
@@ -210,9 +210,8 @@ pub fn build(b: *Build) !void {
     }
     ziglings_step.dependOn(prev_step);
 
-    // Disabled, see issue 272
-    // const test_step = b.step("test", "Run all the tests");
-    // // test_step.dependOn(tests.addCliTests(b, &exercises));
+    const test_step = b.step("test", "Run all the tests");
+    test_step.dependOn(tests.addCliTests(b, &exercises));
 }
 
 var use_color_escapes = false;
@@ -224,181 +223,199 @@ var reset_text: []const u8 = "";
 const ZiglingStep = struct {
     step: Step,
     exercise: Exercise,
-    builder: *Build,
     work_path: []const u8,
 
     result_messages: []const u8 = "",
     result_error_bundle: std.zig.ErrorBundle = std.zig.ErrorBundle.empty,
 
-    pub fn create(builder: *Build, exercise: Exercise, work_path: []const u8) *@This() {
-        const self = builder.allocator.create(@This()) catch unreachable;
+    pub fn create(b: *Build, exercise: Exercise, work_path: []const u8) *ZiglingStep {
+        const self = b.allocator.create(ZiglingStep) catch @panic("OOM");
         self.* = .{
-            .step = Step.init(Step.Options{ .id = .custom, .name = exercise.main_file, .owner = builder, .makeFn = make }),
+            .step = Step.init(.{
+                .id = .custom,
+                .name = exercise.main_file,
+                .owner = b,
+                .makeFn = make,
+            }),
             .exercise = exercise,
-            .builder = builder,
             .work_path = work_path,
         };
         return self;
     }
 
-    fn make(step: *Step, prog_node: *std.Progress.Node) anyerror!void {
-        const self = @fieldParentPtr(@This(), "step", step);
+    fn make(step: *Step, prog_node: *std.Progress.Node) !void {
+        const self = @fieldParentPtr(ZiglingStep, "step", step);
 
         if (self.exercise.skip) {
             print("Skipping {s}\n\n", .{self.exercise.main_file});
 
             return;
         }
-        self.makeInternal(prog_node) catch {
+
+        const exe_path = self.compile(prog_node) catch {
             if (self.exercise.hint.len > 0) {
-                print("\n{s}HINT: {s}{s}", .{ bold_text, self.exercise.hint, reset_text });
+                print("\n{s}HINT: {s}{s}", .{
+                    bold_text, self.exercise.hint, reset_text,
+                });
             }
 
-            print("\n{s}Edit exercises/{s} and run this again.{s}", .{ red_text, self.exercise.main_file, reset_text });
-            print("\n{s}To continue from this zigling, use this command:{s}\n    {s}zig build -Dn={s}{s}\n", .{ red_text, reset_text, bold_text, self.exercise.key(), reset_text });
+            self.help();
             std.os.exit(1);
         };
-    }
 
-    fn makeInternal(self: *@This(), prog_node: *std.Progress.Node) !void {
-        print("Compiling {s}...\n", .{self.exercise.main_file});
+        self.run(exe_path, prog_node) catch {
+            if (self.exercise.hint.len > 0) {
+                print("\n{s}HINT: {s}{s}", .{
+                    bold_text, self.exercise.hint, reset_text,
+                });
+            }
 
-        const exe_file = try self.doCompile(prog_node);
+            self.help();
+            std.os.exit(1);
+        };
+    }
 
+    fn run(self: *ZiglingStep, exe_path: []const u8, _: *std.Progress.Node) !void {
         resetLine();
         print("Checking {s}...\n", .{self.exercise.main_file});
 
-        const cwd = self.builder.build_root.path.?;
-
-        const argv = [_][]const u8{exe_file};
-
-        var child = std.ChildProcess.init(&argv, self.builder.allocator);
-
-        child.cwd = cwd;
-        child.env_map = self.builder.env_map;
-
-        child.stdin_behavior = .Inherit;
-        if (self.exercise.check_stdout) {
-            child.stdout_behavior = .Pipe;
-            child.stderr_behavior = .Inherit;
-        } else {
-            child.stdout_behavior = .Inherit;
-            child.stderr_behavior = .Pipe;
-        }
+        const b = self.step.owner;
 
-        child.spawn() catch |err| {
-            print("{s}Unable to spawn {s}: {s}{s}\n", .{ red_text, argv[0], @errorName(err), reset_text });
+        // Allow up to 1 MB of stdout capture.
+        const max_output_bytes = 1 * 1024 * 1024;
+
+        var result = Child.exec(.{
+            .allocator = b.allocator,
+            .argv = &.{exe_path},
+            .cwd = b.build_root.path.?,
+            .cwd_dir = b.build_root.handle,
+            .max_output_bytes = max_output_bytes,
+        }) catch |err| {
+            print("{s}Unable to spawn {s}: {s}{s}\n", .{
+                red_text, exe_path, @errorName(err), reset_text,
+            });
             return err;
         };
 
-        // Allow up to 1 MB of stdout capture.
-        const max_output_len = 1 * 1024 * 1024;
-        const output = if (self.exercise.check_stdout)
-            try child.stdout.?.reader().readAllAlloc(self.builder.allocator, max_output_len)
+        const raw_output = if (self.exercise.check_stdout)
+            result.stdout
         else
-            try child.stderr.?.reader().readAllAlloc(self.builder.allocator, max_output_len);
-
-        // At this point stdout is closed, wait for the process to terminate.
-        const term = child.wait() catch |err| {
-            print("{s}Unable to spawn {s}: {s}{s}\n", .{ red_text, argv[0], @errorName(err), reset_text });
-            return err;
-        };
+            result.stderr;
 
         // Make sure it exited cleanly.
-        switch (term) {
+        switch (result.term) {
             .Exited => |code| {
                 if (code != 0) {
-                    print("{s}{s} exited with error code {d} (expected {d}){s}\n", .{ red_text, self.exercise.main_file, code, 0, reset_text });
+                    print("{s}{s} exited with error code {d} (expected {d}){s}\n", .{
+                        red_text, self.exercise.main_file, code, 0, reset_text,
+                    });
                     return error.BadExitCode;
                 }
             },
             else => {
-                print("{s}{s} terminated unexpectedly{s}\n", .{ red_text, self.exercise.main_file, reset_text });
+                print("{s}{s} terminated unexpectedly{s}\n", .{
+                    red_text, self.exercise.main_file, reset_text,
+                });
                 return error.UnexpectedTermination;
             },
         }
 
         // Validate the output.
-        const trimOutput = std.mem.trimRight(u8, output, " \r\n");
-        const trimExerciseOutput = std.mem.trimRight(u8, self.exercise.output, " \r\n");
-        if (!std.mem.eql(u8, trimOutput, trimExerciseOutput)) {
+        const output = std.mem.trimRight(u8, raw_output, " \r\n");
+        const exercise_output = std.mem.trimRight(u8, self.exercise.output, " \r\n");
+        if (!std.mem.eql(u8, output, exercise_output)) {
+            const red = red_text;
+            const reset = reset_text;
+
             print(
                 \\
-                \\{s}----------- Expected this output -----------{s}
-                \\"{s}"
-                \\{s}----------- but found -----------{s}
-                \\"{s}"
-                \\{s}-----------{s}
+                \\{s}========= expected this output: =========={s}
+                \\{s}
+                \\{s}========= but found: ====================={s}
+                \\{s}
+                \\{s}=========================================={s}
                 \\
-            , .{ red_text, reset_text, trimExerciseOutput, red_text, reset_text, trimOutput, red_text, reset_text });
+            , .{ red, reset, exercise_output, red, reset, output, red, reset });
             return error.InvalidOutput;
         }
 
-        print("{s}PASSED:\n{s}{s}\n\n", .{ green_text, trimOutput, reset_text });
+        print("{s}PASSED:\n{s}{s}\n\n", .{ green_text, output, reset_text });
     }
 
-    // The normal compile step calls os.exit, so we can't use it as a library :(
-    // This is a stripped down copy of std.build.LibExeObjStep.make.
-    fn doCompile(self: *@This(), prog_node: *std.Progress.Node) ![]const u8 {
-        const builder = self.builder;
+    fn compile(self: *ZiglingStep, prog_node: *std.Progress.Node) ![]const u8 {
+        print("Compiling {s}...\n", .{self.exercise.main_file});
 
-        var zig_args = std.ArrayList([]const u8).init(builder.allocator);
+        const b = self.step.owner;
+        const exercise_path = self.exercise.main_file;
+        const path = join(b.allocator, &.{ self.work_path, exercise_path }) catch
+            @panic("OOM");
+
+        var zig_args = std.ArrayList([]const u8).init(b.allocator);
         defer zig_args.deinit();
 
-        zig_args.append(builder.zig_exe) catch unreachable;
-        zig_args.append("build-exe") catch unreachable;
+        zig_args.append(b.zig_exe) catch @panic("OOM");
+        zig_args.append("build-exe") catch @panic("OOM");
 
-        // Enable C support for exercises that use C functions
+        // Enable C support for exercises that use C functions.
         if (self.exercise.link_libc) {
-            zig_args.append("-lc") catch unreachable;
+            zig_args.append("-lc") catch @panic("OOM");
         }
 
-        const zig_file = join(builder.allocator, &.{ self.work_path, self.exercise.main_file }) catch unreachable;
-        zig_args.append(builder.pathFromRoot(zig_file)) catch unreachable;
+        zig_args.append(b.pathFromRoot(path)) catch @panic("OOM");
 
-        zig_args.append("--cache-dir") catch unreachable;
-        zig_args.append(builder.pathFromRoot(builder.cache_root.path.?)) catch unreachable;
+        zig_args.append("--cache-dir") catch @panic("OOM");
+        zig_args.append(b.pathFromRoot(b.cache_root.path.?)) catch @panic("OOM");
 
-        zig_args.append("--listen=-") catch unreachable;
+        zig_args.append("--listen=-") catch @panic("OOM");
 
         const argv = zig_args.items;
         var code: u8 = undefined;
-        const file_name = self.eval(argv, &code, prog_node) catch |err| {
+        const exe_path = self.eval(argv, &code, prog_node) catch |err| {
             self.printErrors();
 
             switch (err) {
                 error.FileNotFound => {
-                    print("{s}{s}: Unable to spawn the following command: file not found{s}\n", .{ red_text, self.exercise.main_file, reset_text });
+                    print("{s}{s}: Unable to spawn the following command: file not found{s}\n", .{
+                        red_text, self.exercise.main_file, reset_text,
+                    });
                     for (argv) |v| print("{s} ", .{v});
                     print("\n", .{});
                 },
                 error.ExitCodeFailure => {
-                    print("{s}{s}: The following command exited with error code {}:{s}\n", .{ red_text, self.exercise.main_file, code, reset_text });
+                    print("{s}{s}: The following command exited with error code {}:{s}\n", .{
+                        red_text, self.exercise.main_file, code, reset_text,
+                    });
                     for (argv) |v| print("{s} ", .{v});
                     print("\n", .{});
                 },
                 error.ProcessTerminated => {
-                    print("{s}{s}: The following command terminated unexpectedly:{s}\n", .{ red_text, self.exercise.main_file, reset_text });
+                    print("{s}{s}: The following command terminated unexpectedly:{s}\n", .{
+                        red_text, self.exercise.main_file, reset_text,
+                    });
                     for (argv) |v| print("{s} ", .{v});
                     print("\n", .{});
                 },
                 error.ZigIPCError => {
                     print("{s}{s}: The following command failed to communicate the compilation result:{s}\n", .{
-                        red_text,
-                        self.exercise.main_file,
-                        reset_text,
+                        red_text, self.exercise.main_file, reset_text,
+                    });
+                    for (argv) |v| print("{s} ", .{v});
+                    print("\n", .{});
+                },
+                else => {
+                    print("{s}{s}: Unexpected error: {s}{s}\n", .{
+                        red_text, self.exercise.main_file, @errorName(err), reset_text,
                     });
                     for (argv) |v| print("{s} ", .{v});
                     print("\n", .{});
                 },
-                else => {},
             }
 
             return err;
         };
         self.printErrors();
 
-        return file_name;
+        return exe_path;
     }
 
     // Code adapted from `std.Build.execAllowFail and `std.Build.Step.evalZigProcess`.
@@ -501,6 +518,23 @@ const ZiglingStep = struct {
         return result orelse return error.ZigIPCError;
     }
 
+    fn help(self: *ZiglingStep) void {
+        const path = self.exercise.main_file;
+        const key = self.exercise.key();
+
+        print("\n{s}Edit exercises/{s} and run this again.{s}", .{
+            red_text, path, reset_text,
+        });
+
+        const format =
+            \\
+            \\{s}To continue from this zigling, use this command:{s}
+            \\    {s}zig build -Dn={s}{s}
+            \\
+        ;
+        print(format, .{ red_text, reset_text, bold_text, key, reset_text });
+    }
+
     fn printErrors(self: *ZiglingStep) void {
         resetLine();
 
diff --git a/exercises/047_methods.zig b/exercises/047_methods.zig
index 96d4c8e..6b2dbef 100644
--- a/exercises/047_methods.zig
+++ b/exercises/047_methods.zig
@@ -2,9 +2,9 @@
 // Help! Evil alien creatures have hidden eggs all over the Earth
 // and they're starting to hatch!
 //
-// Before you jump into battle, you'll need to know four things:
+// Before you jump into battle, you'll need to know three things:
 //
-// 1. You can attach functions to structs:
+// 1. You can attach functions to structs (and other "type definitions"):
 //
 //     const Foo = struct{
 //         pub fn hello() void {
@@ -12,31 +12,30 @@
 //         }
 //     };
 //
-// 2. A function that is a member of a struct is a "method" and is
-//    called with the "dot syntax" like so:
+// 2. A function that is a member of a struct is "namespaced" within
+//    that struct and is called by specifying the "namespace" and then
+//    using the "dot syntax":
 //
 //     Foo.hello();
 //
-// 3. The NEAT feature of methods is the special parameter named
-//    "self" that takes an instance of that type of struct:
+// 3. The NEAT feature of these functions is that if their first argument
+//    is an instance of the struct (or a pointer to one) then we can use
+//    the instance as the namespace instead of the type:
 //
 //     const Bar = struct{
-//         number: u32,
-//
-//         pub fn printMe(self: Bar) void {
-//             std.debug.print("{}\n", .{self.number});
-//         }
+//         pub fn a(self: Bar) void {}
+//         pub fn b(this: *Bar, other: u8) void {}
+//         pub fn c(bar: *const Bar) void {}
 //     };
 //
-//    (Actually, you can name the first parameter anything, but
-//    please follow convention and use "self".)
-//
-// 4. Now when you call the method on an INSTANCE of that struct
-//    with the "dot syntax", the instance will be automatically
-//    passed as the "self" parameter:
+//    var bar = Bar{};
+//    bar.a() // is equivalent to Bar.a(bar)
+//    bar.b(3) // is equivalent to Bar.b(&bar, 3)
+//    bar.c() // is equivalent to Bar.c(&bar)
 //
-//     var my_bar = Bar{ .number = 2000 };
-//     my_bar.printMe(); // prints "2000"
+//    Notice that the name of the parameter doesn't matter. Some use
+//    self, others use a lowercase version of the type name, but feel
+//    free to use whatever is most appropriate.
 //
 // Okay, you're armed.
 //
diff --git a/exercises/060_floats.zig b/exercises/060_floats.zig
index 8ba51db..1320171 100644
--- a/exercises/060_floats.zig
+++ b/exercises/060_floats.zig
@@ -1,10 +1,11 @@
 //
 // Zig has support for IEEE-754 floating-point numbers in these
 // specific sizes: f16, f32, f64, f80, and f128. Floating point
-// literals may be written in scientific notation:
+// literals may be written in the same ways as integers but also
+// in scientific notation:
 //
-//     const a1: f32 = 1200.0;     // 1,200
-//     const a2: f32 = 1.2e+3;     // 1,200
+//     const a1: f32 = 1200;       //    1,200
+//     const a2: f32 = 1.2e+3;     //    1,200
 //     const b1: f32 = -500_000.0; // -500,000
 //     const b2: f32 = -5.0e+5;    // -500,000
 //
@@ -22,12 +23,14 @@
 //     const pi: f16 = 3.1415926535;   // rounds to 3.140625
 //     const av: f16 = 6.02214076e+23; // Avogadro's inf(inity)!
 //
-// A float literal has a decimal point. When performing math
-// operations with numeric literals, ensure the types match. Zig
-// does not perform unsafe type coercions behind your back:
+// When performing math operations with numeric literals, ensure
+// the types match. Zig does not perform unsafe type coercions
+// behind your back:
 //
-//     var foo: f16 = 13.5 * 5;   // ERROR!
-//     var foo: f16 = 13.5 * 5.0; // No problem, both are floats
+//    var foo: f16 = 5; // NO ERROR
+//
+//    var foo: u16 = 5; // A literal of a different type
+//    var bar: f16 = foo; // ERROR
 //
 // Please fix the two float problems with this program and
 // display the result as a whole number.
diff --git a/test/tests.zig b/test/tests.zig
index 8786d91..752ca50 100644
--- a/test/tests.zig
+++ b/test/tests.zig
@@ -20,15 +20,14 @@ pub fn addCliTests(b: *std.Build, exercises: []const Exercise) *Step {
 
     // We should use a temporary path, but it will make the implementation of
     // `build.zig` more complex.
-    const outdir = "patches/healed";
+    const work_path = "patches/healed";
 
-    fs.cwd().makePath(outdir) catch |err| {
-        return fail(step, "unable to make '{s}': {s}\n", .{ outdir, @errorName(err) });
-    };
-    heal(b.allocator, exercises, outdir) catch |err| {
-        return fail(step, "unable to heal exercises: {s}\n", .{@errorName(err)});
+    fs.cwd().makePath(work_path) catch |err| {
+        return fail(step, "unable to make '{s}': {s}\n", .{ work_path, @errorName(err) });
     };
 
+    const heal_step = HealStep.create(b, exercises, work_path);
+
     {
         // Test that `zig build -Dhealed -Dn=n test` selects the nth exercise.
         const case_step = createCase(b, "case-1");
@@ -49,6 +48,8 @@ pub fn addCliTests(b: *std.Build, exercises: []const Exercise) *Step {
             else
                 expectStdErrMatch(cmd, ex.output);
 
+            cmd.step.dependOn(&heal_step.step);
+
             case_step.dependOn(&cmd.step);
         }
 
@@ -72,6 +73,8 @@ pub fn addCliTests(b: *std.Build, exercises: []const Exercise) *Step {
             cmd.expectStdOutEqual("");
             expectStdErrMatch(cmd, b.fmt("{s} skipped", .{ex.main_file}));
 
+            cmd.step.dependOn(&heal_step.step);
+
             case_step.dependOn(&cmd.step);
         }
 
@@ -86,6 +89,7 @@ pub fn addCliTests(b: *std.Build, exercises: []const Exercise) *Step {
         const cmd = b.addSystemCommand(&.{ b.zig_exe, "build", "-Dhealed" });
         cmd.setName("zig build -Dhealed");
         cmd.expectExitCode(0);
+        cmd.step.dependOn(&heal_step.step);
 
         const stderr = cmd.captureStdErr();
         const verify = CheckStep.create(b, exercises, stderr, true);
@@ -107,6 +111,7 @@ pub fn addCliTests(b: *std.Build, exercises: []const Exercise) *Step {
         );
         cmd.setName("zig build -Dhealed -Dn=1 start");
         cmd.expectExitCode(0);
+        cmd.step.dependOn(&heal_step.step);
 
         const stderr = cmd.captureStdErr();
         const verify = CheckStep.create(b, exercises, stderr, false);
@@ -126,14 +131,16 @@ pub fn addCliTests(b: *std.Build, exercises: []const Exercise) *Step {
         cmd.expectExitCode(1);
         expectStdErrMatch(cmd, exercises[0].hint);
 
+        cmd.step.dependOn(&heal_step.step);
+
         case_step.dependOn(&cmd.step);
 
         step.dependOn(case_step);
     }
 
-    // Don't add the cleanup step, since it may delete outdir while a test case
-    // is running.
-    //const cleanup = b.addRemoveDirTree(outdir);
+    // Don't add the cleanup step, since it may delete work_path while a test
+    // case is running.
+    //const cleanup = b.addRemoveDirTree(work_path);
     //step.dependOn(&cleanup.step);
 
     return step;
@@ -315,8 +322,38 @@ fn fail(step: *Step, comptime format: []const u8, args: anytype) *Step {
     return step;
 }
 
+// A step that heals exercises.
+const HealStep = struct {
+    step: Step,
+    exercises: []const Exercise,
+    work_path: []const u8,
+
+    pub fn create(owner: *Build, exercises: []const Exercise, work_path: []const u8) *HealStep {
+        const self = owner.allocator.create(HealStep) catch @panic("OOM");
+        self.* = .{
+            .step = Step.init(.{
+                .id = .custom,
+                .name = "heal",
+                .owner = owner,
+                .makeFn = make,
+            }),
+            .exercises = exercises,
+            .work_path = work_path,
+        };
+
+        return self;
+    }
+
+    fn make(step: *Step, _: *std.Progress.Node) !void {
+        const b = step.owner;
+        const self = @fieldParentPtr(HealStep, "step", step);
+
+        return heal(b.allocator, self.exercises, self.work_path);
+    }
+};
+
 // Heals all the exercises.
-fn heal(allocator: Allocator, exercises: []const Exercise, outdir: []const u8) !void {
+fn heal(allocator: Allocator, exercises: []const Exercise, work_path: []const u8) !void {
     const join = fs.path.join;
 
     const exercises_path = "exercises";
@@ -331,7 +368,7 @@ fn heal(allocator: Allocator, exercises: []const Exercise, outdir: []const u8) !
             const patch_name = try fmt.allocPrint(allocator, "{s}.patch", .{name});
             break :b try join(allocator, &.{ patches_path, patch_name });
         };
-        const output = try join(allocator, &.{ outdir, ex.main_file });
+        const output = try join(allocator, &.{ work_path, ex.main_file });
 
         const argv = &.{ "patch", "-i", patch, "-o", output, "-s", file };