feat(cli): add initial validate-config action

src/cli/action.zig

@@ -9,6 +9,7 @@ const list_keybinds = @import("list_keybinds.zig");
 const list_themes = @import("list_themes.zig");
 const list_colors = @import("list_colors.zig");
 const show_config = @import("show_config.zig");
+const validate_config = @import("validate_config.zig");
 
 /// Special commands that can be invoked via CLI flags. These are all
 /// invoked by using `+<action>` as a CLI flag. The only exception is
@@ -35,6 +36,9 @@ pub const Action = enum {
     /// Dump the config to stdout
     @"show-config",
 
+    // Validate passed config file
+    @"validate-config",
+
     pub const Error = error{
         /// Multiple actions were detected. You can specify at most one
         /// action on the CLI otherwise the behavior desired is ambiguous.
@@ -124,6 +128,7 @@ pub const Action = enum {
             .@"list-themes" => try list_themes.run(alloc),
             .@"list-colors" => try list_colors.run(alloc),
             .@"show-config" => try show_config.run(alloc),
+            .@"validate-config" => try validate_config.run(alloc),
         };
     }
 

src/cli/validate_config.zig

@@ -0,0 +1,59 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const args = @import("args.zig");
+const Action = @import("action.zig").Action;
+const Config = @import("../config.zig").Config;
+const cli = @import("../cli.zig");
+
+pub const Options = struct {
+    /// The path of the config file to validate
+    @"config-file": ?[:0]const u8 = null,
+
+    pub fn deinit(self: Options) void {
+        _ = self;
+    }
+
+    /// Enables "-h" and "--help" to work.
+    pub fn help(self: Options) !void {
+        _ = self;
+        return Action.help_error;
+    }
+};
+
+/// The `validate-config` command is used to validate a Ghostty config
+pub fn run(alloc: std.mem.Allocator) !u8 {
+    var opts: Options = .{};
+    defer opts.deinit();
+
+    {
+        var iter = try std.process.argsWithAllocator(alloc);
+        defer iter.deinit();
+        try args.parse(Options, alloc, &opts, &iter);
+    }
+
+    const stdout = std.io.getStdOut().writer();
+
+    // If a config path is passed, validate it, otherwise validate usual config options
+    if (opts.@"config-file") |config_path| {
+        const cwd = std.fs.cwd();
+
+        if (cwd.openFile(config_path, .{})) |file| {
+            defer file.close();
+
+            var cfg = try Config.default(alloc);
+            defer cfg.deinit();
+
+            var buf_reader = std.io.bufferedReader(file.reader());
+            var iter = cli.args.lineIterator(buf_reader.reader());
+            try cfg.loadIter(alloc, &iter);
+            try cfg.loadRecursiveFiles(alloc);
+            try cfg.finalize();
+        } else |err| {
+            try stdout.print("{any}", .{err});
+        }
+    } else {
+        _ = try Config.load(alloc);
+    }
+
+    return 0;
+}