More work on OAR packing utility

build.zig

@@ -36,6 +36,7 @@ pub fn build(builder: *std.build.Builder) void {
     {
         const tests = builder.addTestExe("test", "./src/tests.zig");
 
+        tests.addPackage(core_pkg);
         tests.setTarget(target);
         tests.setBuildMode(mode);
         builder.step("test", "Run unit tests").dependOn(&tests.step);

src/core/io.zig

@@ -187,6 +187,23 @@ test "Spliterating text" {
 ///
 pub const Writer = meta.Function(@sizeOf(usize), []const u8, usize);
 
+///
+/// Returns `true` if `elements` starts with the characters in `with`, otherwise `false`.
+///
+pub fn begins(comptime Element: type, elements: []const Element, with: []const Element) bool {
+    if (elements.len < with.len) return false;
+
+    return equals(Element, elements[0 .. with.len], with);
+}
+
+test "Check memory begins with" {
+    const bytes_sequence = &.{69, 42};
+    const testing = std.testing;
+
+    try testing.expect(begins(u8, &.{69, 42, 0, 89}, bytes_sequence));
+    try testing.expect(!begins(u8, &.{69, 89, 42, 0}, bytes_sequence));
+}
+
 ///
 /// Returns `true` if `this` is the same length and contains the same data as `that`, otherwise
 /// `false`.
@@ -203,7 +220,7 @@ pub fn equals(comptime Element: type, this: []const Element, that: []const Eleme
     return true;
 }
 
-test "Memory buffers equal" {
+test "Check memory is equals" {
     const bytes_sequence = &.{69, 42, 0};
     const testing = std.testing;
 

src/oar/main.zig

@@ -76,7 +76,7 @@ pub const Path = extern struct {
     /// Returns `true` if `this_path` is equal to `that_path, otherwise `false`.
     ///
     pub fn equals(this_path: Path, that_path: Path) bool {
-        return core.io.equalsBytes(this_path.buffer[0 ..this_path.
+        return core.io.equals(u8, this_path.buffer[0 ..this_path.
             length], that_path.buffer[0 .. that_path.length]);
     }
 
@@ -145,44 +145,54 @@ pub const Path = extern struct {
     pub const seperator = '/';
 };
 
+test "Path" {
+    const testing = std.testing;
+    const empty_path = Path.empty;
+
+    try testing.expectEqual(empty_path.length, 0);
+    try testing.expect(empty_path.equals(Path.empty));
+
+    const joined_component_path = try Path.joined(&.{"path", "to/my", "/file"});
+    const joined_normalized_path = try Path.joined(&.{"path/to/my/file"});
+
+    try testing.expectEqual(empty_path.length, joined_normalized_path.length);
+    try testing.expect(joined_component_path.equals(joined_normalized_path));
+}
+
 ///
 /// Starts the **O**na **Ar**chive packer utility.
 ///
-pub fn main() !u8 {
+pub fn main() u8 {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 
-    defer _ = gpa.deinit();
+    defer std.debug.assert(!gpa.deinit());
 
-    const process = std.process;
     const allocator = gpa.allocator();
-    const args = try process.argsAlloc(allocator);
+    const out_writer = std.io.getStdOut().writer();
+    const process = std.process;
+
+    const args = process.argsAlloc(allocator) catch {
+        try out_writer.print("Failed to allocate args memory", .{});
+
+        return 1;
+    };
 
     defer process.argsFree(allocator, args);
 
-    const outWriter = std.io.getStdOut().writer();
+    if (args.len < 2) {
+        try out_writer.print("Usage: oar [OPTION]... [FILE]...", .{});
+        try out_writer.print("Options and arguments", .{});
 
-    if (args.len > 1) {
-        const command = args[1];
-        const io = core.io;
-
-        if (io.equalsBytes(command, "pack")) {
         return 0;
     }
 
-        if (io.equalsBytes(command, "unpack")) {
+    const arg = std.mem.sliceTo(args[1], 0);
+
+    if (core.io.begins(arg, "--create")) {
         return 0;
     }
 
-        try outWriter.print("Unknown command: {s}", .{command});
-
-        return 1;
-    }
-
-    try outWriter.print("{s}", .{args[0]});
+    try out_writer.print("Unrecognized command-line option `{s}`", .{arg});
 
     return 0;
 }
-
-test {
-
-}