refactor(cli/init): deduplicate asset creation logic (#16294)

src/cli/init_command.zig

@@ -60,9 +60,57 @@ pub const InitCommand = struct {
         }
     }
 
-    const default_gitignore = @embedFile("gitignore-for-init");
-    const default_tsconfig = @embedFile("tsconfig-for-init.json");
-    const README = @embedFile("README-for-init.md");
+    const Assets = struct {
+        // "known" assets
+        const @".gitignore" = @embedFile("init/gitignore.default");
+        const @"tsconfig.json" = @embedFile("init/tsconfig.default.json");
+        const @"README.md" = @embedFile("init/README.default.md");
+
+        /// Create a new asset file, overriding anything that already exists. Known
+        /// assets will have their contents pre-populated; otherwise the file will be empty.
+        fn create(comptime asset_name: []const u8, args: anytype) !void {
+            const is_template = comptime (@TypeOf(args) != @TypeOf(null)) and @typeInfo(@TypeOf(args)).Struct.fields.len > 0;
+            return createFull(asset_name, asset_name, "", is_template, args);
+        }
+
+        fn createNew(filename: []const u8, contents: []const u8) !void {
+            var file = try std.fs.cwd().createFile(filename, .{ .truncate = true });
+            defer file.close();
+            try file.writeAll(contents);
+
+            Output.prettyln(" + <r><d>{s}<r>", .{filename});
+            Output.flush();
+        }
+
+        fn createFull(
+            /// name of possibly-existing asset
+            comptime asset_name: []const u8,
+            /// name of asset file to create
+            filename: []const u8,
+            /// optionally add a suffix to the end of the `+ filename` message. Must have a leading space.
+            comptime message_suffix: []const u8,
+            /// Treat the asset as a format string, using `args` to populate it. Only applies to known assets.
+            comptime is_template: bool,
+            /// Format arguments
+            args: anytype,
+        ) !void {
+            var file = try std.fs.cwd().createFile(filename, .{ .truncate = true });
+            defer file.close();
+
+            // Write contents of known assets to the new file. Template assets get formatted.
+            if (comptime @hasDecl(Assets, asset_name)) {
+                const asset = @field(Assets, asset_name);
+                if (comptime is_template) {
+                    try file.writer().print(asset, args);
+                } else {
+                    try file.writeAll(asset);
+                }
+            }
+
+            Output.prettyln(" + <r><d>{s}{s}<r>", .{ filename, message_suffix });
+            Output.flush();
+        }
+    };
 
     // TODO: unicode case folding
     fn normalizePackageName(allocator: std.mem.Allocator, input: []const u8) ![]const u8 {
@@ -381,21 +429,15 @@ pub const InitCommand = struct {
                 }
             }
 
-            var entry = try cwd.createFile(fields.entry_point, .{ .truncate = true });
-            entry.writeAll("console.log(\"Hello via Bun!\");") catch {};
-            entry.close();
-            Output.prettyln(" + <r><d>{s}<r>", .{fields.entry_point});
-            Output.flush();
+            Assets.createNew(fields.entry_point, "console.log(\"Hello via Bun!\");") catch {
+                // suppress
+            };
         }
 
         if (steps.write_gitignore) {
-            brk: {
-                var file = std.fs.cwd().createFileZ(".gitignore", .{ .truncate = true }) catch break :brk;
-                defer file.close();
-                file.writeAll(default_gitignore) catch break :brk;
-                Output.prettyln(" + <r><d>.gitignore<r>", .{});
-                Output.flush();
-            }
+            Assets.create(".gitignore", .{}) catch {
+                // suppressed
+            };
         }
 
         if (steps.write_tsconfig) {
@@ -406,27 +448,18 @@ pub const InitCommand = struct {
                     "tsconfig.json"
                 else
                     "jsconfig.json";
-                var file = std.fs.cwd().createFileZ(filename, .{ .truncate = true }) catch break :brk;
-                defer file.close();
-                file.writeAll(default_tsconfig) catch break :brk;
-                Output.prettyln(" + <r><d>{s}<r><d> (for editor auto-complete)<r>", .{filename});
-                Output.flush();
+                Assets.createFull("tsconfig.json", filename, " (for editor autocomplete)", false, .{}) catch break :brk;
             }
         }
 
         if (steps.write_readme) {
-            brk: {
-                const filename = "README.md";
-                var file = std.fs.cwd().createFileZ(filename, .{ .truncate = true }) catch break :brk;
-                defer file.close();
-                file.writer().print(README, .{
-                    .name = fields.name,
-                    .bunVersion = Environment.version_string,
-                    .entryPoint = fields.entry_point,
-                }) catch break :brk;
-                Output.prettyln(" + <r><d>{s}<r>", .{filename});
-                Output.flush();
-            }
+            Assets.create("README.md", .{
+                .name = fields.name,
+                .bunVersion = Environment.version_string,
+                .entryPoint = fields.entry_point,
+            }) catch {
+                // suppressed
+            };
         }
 
         if (fields.entry_point.len > 0) {