make Package.Path support string escape formatting

lib/std/zig.zig

@@ -1,6 +1,6 @@
 const std = @import("std.zig");
 const tokenizer = @import("zig/tokenizer.zig");
-const fmt = @import("zig/fmt.zig");
+pub const fmt = @import("zig/fmt.zig");
 const assert = std.debug.assert;
 
 pub const ErrorBundle = @import("zig/ErrorBundle.zig");

lib/std/zig/fmt.zig

@@ -13,7 +13,7 @@ fn formatId(
         return writer.writeAll(bytes);
     }
     try writer.writeAll("@\"");
-    try formatEscapes(bytes, "", options, writer);
+    try stringEscape(bytes, "", options, writer);
     try writer.writeByte('"');
 }
 
@@ -47,7 +47,7 @@ test "isValidId" {
 /// Print the string as escaped contents of a double quoted or single-quoted string.
 /// Format `{}` treats contents as a double-quoted string.
 /// Format `{'}` treats contents as a single-quoted string.
-fn formatEscapes(
+pub fn stringEscape(
     bytes: []const u8,
     comptime fmt: []const u8,
     options: std.fmt.FormatOptions,
@@ -90,7 +90,7 @@ fn formatEscapes(
 /// The format specifier must be one of:
 ///  * `{}` treats contents as a double-quoted string.
 ///  * `{'}` treats contents as a single-quoted string.
-pub fn fmtEscapes(bytes: []const u8) std.fmt.Formatter(formatEscapes) {
+pub fn fmtEscapes(bytes: []const u8) std.fmt.Formatter(stringEscape) {
     return .{ .data = bytes };
 }
 

src/Package.zig

@@ -89,7 +89,23 @@ pub const Path = struct {
         options: std.fmt.FormatOptions,
         writer: anytype,
     ) !void {
-        _ = options;
+        if (fmt_string.len == 1) {
+            // Quote-escape the string.
+            const stringEscape = std.zig.fmt.stringEscape;
+            const f = switch (fmt_string[0]) {
+                'q' => "",
+                '\'' => '\'',
+                else => @compileError("unsupported format string: " ++ fmt_string),
+            };
+            if (self.root_dir.path) |p| {
+                try stringEscape(p, f, options, writer);
+                if (self.sub_path.len > 0) try writer.writeAll(fs.path.sep_str);
+            }
+            if (self.sub_path.len > 0) {
+                try stringEscape(self.sub_path, f, options, writer);
+            }
+            return;
+        }
         if (fmt_string.len > 0)
             std.fmt.invalidFmtError(fmt_string, self);
         if (self.root_dir.path) |p| {