Improve errors in parse API

src/Server/parse.zig

@@ -19,6 +19,12 @@ const message = @import("./message.zig");
 const Message = message.Message;
 const Payload = @import("./Payload.zig");
 
+pub const Error = error{
+    EndOfStream,
+    ReadFailed,
+    InvalidStream,
+};
+
 const client_control = StaticStringMap(message.Control).initComptime(
     .{
         // {"INFO", .info},
@@ -36,7 +42,7 @@ const client_control = StaticStringMap(message.Control).initComptime(
     },
 );
 
-pub fn control(in: *Reader) !message.Control {
+pub fn control(in: *Reader) Error!message.Control {
     const longest_ctrl = comptime blk: {
         var min_len = 0;
         for (client_control.keys()) |ctrl| {
@@ -54,7 +60,7 @@ pub fn control(in: *Reader) !message.Control {
                 in.toss(str.len);
                 return ctrl;
             } else if (str.len >= longest_ctrl) {
-                return error.InvalidControl;
+                return error.InvalidStream;
             }
         }
         log.debug("filling more in control.", .{});
@@ -109,13 +115,13 @@ test control {
         var in: std.testing.Reader = .init(&buf, &.{
             .{ .buffer = "CONNECC" },
         });
-        try std.testing.expectError(error.InvalidControl, control(&in.interface));
+        try std.testing.expectError(error.InvalidStream, control(&in.interface));
     }
 }
 
 /// The return value is owned by the reader passed to this function.
 /// Operations that modify the readers buffer invalidates this value.
-pub fn @"pub"(in: *Reader) !Message.Pub {
+pub fn @"pub"(in: *Reader) Error!Message.Pub {
     // TODO: Add pedantic option.
     // See: https://docs.nats.io/reference/reference-protocols/nats-protocol#syntax-1
 
@@ -127,7 +133,7 @@ pub fn @"pub"(in: *Reader) !Message.Pub {
                 if (in.buffered().len > iter.index) {
                     if (in.buffered()[iter.index] == '\r') {
                         const bytes_str = second;
-                        const bytes = try parseUnsigned(usize, bytes_str, 10);
+                        const bytes = parseUnsigned(usize, bytes_str, 10) catch return error.InvalidStream;
 
                         if (in.buffered().len < iter.index + bytes + 4) {
                             try in.fill(iter.index + bytes + 4);
@@ -147,7 +153,7 @@ pub fn @"pub"(in: *Reader) !Message.Pub {
 
                     const reply_to = second;
                     if (iter.next()) |bytes_str| {
-                        const bytes = try parseUnsigned(usize, bytes_str, 10);
+                        const bytes = parseUnsigned(usize, bytes_str, 10) catch return error.InvalidStream;
 
                         if (in.buffered().len > iter.index and in.buffered()[iter.index] == '\r') {
                             if (in.buffered().len < iter.index + bytes + 4) {
@@ -260,7 +266,7 @@ test @"pub" {
 
 /// The return value is owned by the reader passed to this function.
 /// Operations that modify the readers buffer invalidates this value.
-pub fn sub(in: *Reader) !Message.Sub {
+pub fn sub(in: *Reader) Error!Message.Sub {
     // TODO: Add pedantic option.
     // See: https://docs.nats.io/reference/reference-protocols/nats-protocol#syntax-1
 
@@ -378,7 +384,7 @@ test sub {
 
 /// The return value is owned by the reader passed to this function.
 /// Operations that modify the readers buffer invalidates this value.
-pub fn unsub(in: *Reader) !Message.Unsub {
+pub fn unsub(in: *Reader) Error!Message.Unsub {
     // TODO: Add pedantic option.
     // See: https://docs.nats.io/reference/reference-protocols/nats-protocol#syntax-1
 
@@ -403,7 +409,7 @@ pub fn unsub(in: *Reader) !Message.Unsub {
                 }
                 if (iter.next()) |max_msgs_str| {
                     if (in.buffered().len > iter.index and in.buffered()[iter.index] == '\r') {
-                        const max_msgs = try parseUnsigned(usize, max_msgs_str, 10);
+                        const max_msgs = parseUnsigned(usize, max_msgs_str, 10) catch return error.InvalidStream;
 
                         if (in.buffered().len < iter.index + 2) {
                             try in.fill(iter.index + 2);
@@ -429,7 +435,7 @@ pub fn unsub(in: *Reader) !Message.Unsub {
                 const sid = iter.next() orelse return error.EndOfStream;
                 const max_msgs = if (iter.next()) |max_msgs_str| blk: {
                     log.debug("max_msgs: {any}", .{max_msgs_str});
-                    break :blk try parseUnsigned(usize, max_msgs_str, 10);
+                    break :blk parseUnsigned(usize, max_msgs_str, 10) catch return error.InvalidStream;
                 } else null;
                 return .{
                     .sid = sid,
@@ -515,7 +521,7 @@ test unsub {
 
 /// The return value is owned by the reader passed to this function.
 /// Operations that modify the readers buffer invalidates this value.
-pub fn hpub(in: *Reader) !Message.HPub {
+pub fn hpub(in: *Reader) Error!Message.HPub {
     // TODO: Add pedantic option.
     // See: https://docs.nats.io/reference/reference-protocols/nats-protocol#syntax-1
     while (true) {
@@ -529,8 +535,8 @@ pub fn hpub(in: *Reader) !Message.HPub {
                             const header_bytes_str = second;
                             const total_bytes_str = third;
 
-                            const header_bytes = try parseUnsigned(usize, header_bytes_str, 10);
+                            const header_bytes = parseUnsigned(usize, header_bytes_str, 10) catch return error.InvalidStream;
-                            const total_bytes = try parseUnsigned(usize, total_bytes_str, 10);
+                            const total_bytes = parseUnsigned(usize, total_bytes_str, 10) catch return error.InvalidStream;
 
                             if (in.buffered().len < iter.index + total_bytes + 4) {
                                 try in.fill(iter.index + total_bytes + 4);
@@ -555,8 +561,8 @@ pub fn hpub(in: *Reader) !Message.HPub {
                     const header_bytes_str = third;
                     if (iter.next()) |total_bytes_str| {
                         if (in.buffered().len > iter.index and in.buffered()[iter.index] == '\r') {
-                            const header_bytes = try parseUnsigned(usize, header_bytes_str, 10);
+                            const header_bytes = parseUnsigned(usize, header_bytes_str, 10) catch return error.InvalidStream;
-                            const total_bytes = try parseUnsigned(usize, total_bytes_str, 10);
+                            const total_bytes = parseUnsigned(usize, total_bytes_str, 10) catch return error.InvalidStream;
 
                             if (in.buffered().len < iter.index + total_bytes + 4) {
                                 try in.fill(iter.index + total_bytes + 4);
@@ -624,12 +630,7 @@ test hpub {
     // TODO: more tests
 }
 
-pub fn connect(alloc: Allocator, in: *Reader) error{
+pub fn connect(alloc: Allocator, in: *Reader) (error{OutOfMemory} || Error)!Message.Connect {
-    EndOfStream,
-    ReadFailed,
-    OutOfMemory,
-    InvalidStream,
-}!Message.Connect {
     // for storing the json string
     var connect_string_writer_allocating: AllocatingWriter = .init(alloc);
     defer connect_string_writer_allocating.deinit();