From f30510f122f1a6c87bdde04d25d71c5ce38c9a1c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@jakstys.lt>
Date: Tue, 28 Jun 2022 16:44:44 +0300
Subject: [PATCH] wrap errors in real code with quotes

---
 src/ErrCtx.zig       | 7 +++++--
 src/unix2db/main.zig | 6 +++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/ErrCtx.zig b/src/ErrCtx.zig
index 3325e5a..8cf17bf 100644
--- a/src/ErrCtx.zig
+++ b/src/ErrCtx.zig
@@ -31,6 +31,9 @@ pub fn write(self: *ErrCtx, bytes: []const u8) error{}!usize {
 
 const Writer = std.io.Writer(*ErrCtx, error{}, write);
 
+// writer is private, because fmt.print(...) can do multiple write(...) calls
+// for a single fmt.print(...). It is too easy to mis-use; therefore use the
+// wrappers below.
 fn writer(self: *ErrCtx) Writer {
     return Writer{ .context = self };
 }
@@ -51,7 +54,7 @@ pub fn returnf(
     args: anytype,
     comptime ret: anytype,
 ) @TypeOf(ret) {
-    self.writer().print(format, args) catch unreachable;
+    self.print(format, args);
     return ret;
 }
 
@@ -61,7 +64,7 @@ pub fn wrap(self: *ErrCtx, comptime msg: []const u8) *ErrCtx {
 }
 
 pub fn wrapf(self: *ErrCtx, comptime format: []const u8, args: anytype) *ErrCtx {
-    self.writer().print(format, args) catch unreachable;
+    self.print(format, args);
     return self;
 }
 
diff --git a/src/unix2db/main.zig b/src/unix2db/main.zig
index 72c6622..4d64452 100644
--- a/src/unix2db/main.zig
+++ b/src/unix2db/main.zig
@@ -70,11 +70,11 @@ fn execute(
     // https://github.com/ziglang/zig/issues/2473
     var errc = ErrCtx{};
     var passwdFile = fs.cwd().openFile(passwdFname, .{ .mode = .read_only }) catch |err|
-        return fail(errc.wrapf("open {s}", .{passwdFname}), stderr, err);
+        return fail(errc.wrapf("open '{s}'", .{passwdFname}), stderr, err);
     defer passwdFile.close();
 
     var groupFile = fs.cwd().openFile(groupFname, .{ .mode = .read_only }) catch |err|
-        return fail(errc.wrapf("open {s}", .{groupFname}), stderr, err);
+        return fail(errc.wrapf("open '{s}'", .{groupFname}), stderr, err);
     defer groupFile.close();
 
     var users = User.fromReader(allocator, &errc, passwdFile.reader()) catch |err|
@@ -151,7 +151,7 @@ test "trivial error: missing passwd file" {
 
     const exit_code = execute(allocator, stdout.writer(), stderr.writer(), args[0..]);
     try testing.expectEqual(@as(u8, 1), exit_code);
-    try testing.expectEqualStrings(stderr.items, "ERROR FileNotFound: ./passwd: open \n");
+    try testing.expectEqualStrings(stderr.items, "ERROR FileNotFound: open './passwd'\n");
 }
 
 test "fail" {