From a315f8f32e2f806f79795d5b51f9f607c6b9b51e Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Thu, 6 Nov 2025 08:14:13 -0800
Subject: [PATCH] nix: add ucs-detect

This makes `ucs-detect` available in our Nix environment so that we can
run tests on our Unicode support. In the future, I'd like to modify our
CI to run this too.

This also adds a `./test/ucs-detect.sh` script that runs `ucs-detect`
with consistent options that match the upstream test styles.
---
 flake.nix                   | 10 ++++++++-
 nix/devShell.nix            |  5 +++++
 nix/pkgs/blessed.nix        | 37 +++++++++++++++++++++++++++++++++
 nix/pkgs/ucs-detect.nix     | 41 +++++++++++++++++++++++++++++++++++++
 nix/{ => pkgs}/wraptest.nix |  0
 test/ucs-detect.sh          | 11 ++++++++++
 6 files changed, 103 insertions(+), 1 deletion(-)
 create mode 100644 nix/pkgs/blessed.nix
 create mode 100644 nix/pkgs/ucs-detect.nix
 rename nix/{ => pkgs}/wraptest.nix (100%)
 create mode 100755 test/ucs-detect.sh

diff --git a/flake.nix b/flake.nix
index 9ede1c788..3dcfef185 100644
--- a/flake.nix
+++ b/flake.nix
@@ -50,8 +50,16 @@
         in {
           devShell.${system} = pkgs.callPackage ./nix/devShell.nix {
             zig = zig.packages.${system}."0.15.2";
-            wraptest = pkgs.callPackage ./nix/wraptest.nix {};
+            wraptest = pkgs.callPackage ./nix/pkgs/wraptest.nix {};
             zon2nix = zon2nix;
+
+            python3 = pkgs.python3.override {
+              self = pkgs.python3;
+              packageOverrides = pyfinal: pyprev: {
+                blessed = pyfinal.callPackage ./nix/pkgs/blessed.nix {};
+                ucs-detect = pyfinal.callPackage ./nix/pkgs/ucs-detect.nix {};
+              };
+            };
           };
 
           packages.${system} = let
diff --git a/nix/devShell.nix b/nix/devShell.nix
index 0c97ec0da..4aaf4ef5c 100644
--- a/nix/devShell.nix
+++ b/nix/devShell.nix
@@ -136,6 +136,11 @@ in
         blueprint-compiler
         libadwaita
         gtk4
+
+        # Python packages
+        (python3.withPackages (python-pkgs: [
+          python-pkgs.ucs-detect
+        ]))
       ]
       ++ lib.optionals stdenv.hostPlatform.isLinux [
         # My nix shell environment installs the non-interactive version
diff --git a/nix/pkgs/blessed.nix b/nix/pkgs/blessed.nix
new file mode 100644
index 000000000..8b6728f43
--- /dev/null
+++ b/nix/pkgs/blessed.nix
@@ -0,0 +1,37 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchPypi,
+  pythonOlder,
+  flit-core,
+  six,
+  wcwidth,
+}:
+buildPythonPackage rec {
+  pname = "blessed";
+  version = "1.23.0";
+  pyproject = true;
+
+  disabled = pythonOlder "3.7";
+
+  src = fetchPypi {
+    inherit pname version;
+    hash = "sha256-VlkaMpZvcE9hMfFACvQVHZ6PX0FEEzpcoDQBl2Pe53s=";
+  };
+
+  build-system = [flit-core];
+
+  propagatedBuildInputs = [
+    wcwidth
+    six
+  ];
+
+  doCheck = false;
+
+  meta = with lib; {
+    homepage = "https://github.com/jquast/blessed";
+    description = "Thin, practical wrapper around terminal capabilities in Python";
+    maintainers = [];
+    license = licenses.mit;
+  };
+}
diff --git a/nix/pkgs/ucs-detect.nix b/nix/pkgs/ucs-detect.nix
new file mode 100644
index 000000000..07ec6c2fc
--- /dev/null
+++ b/nix/pkgs/ucs-detect.nix
@@ -0,0 +1,41 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchPypi,
+  pythonOlder,
+  setuptools,
+  # Dependencies
+  blessed,
+  wcwidth,
+  pyyaml,
+}:
+buildPythonPackage rec {
+  pname = "ucs-detect";
+  version = "1.0.8";
+  pyproject = true;
+
+  disabled = pythonOlder "3.8";
+
+  src = fetchPypi {
+    inherit version;
+    pname = "ucs_detect";
+    hash = "sha256-ihB+tZCd6ykdeXYxc6V1Q6xALQ+xdCW5yqSL7oppqJc=";
+  };
+
+  dependencies = [
+    blessed
+    wcwidth
+    pyyaml
+  ];
+
+  nativeBuildInputs = [setuptools];
+
+  doCheck = false;
+
+  meta = with lib; {
+    description = "Measures number of Terminal column cells of wide-character codes";
+    homepage = "https://github.com/jquast/ucs-detect";
+    license = licenses.mit;
+    maintainers = [];
+  };
+}
diff --git a/nix/wraptest.nix b/nix/pkgs/wraptest.nix
similarity index 100%
rename from nix/wraptest.nix
rename to nix/pkgs/wraptest.nix
diff --git a/test/ucs-detect.sh b/test/ucs-detect.sh
new file mode 100755
index 000000000..79d5fca0c
--- /dev/null
+++ b/test/ucs-detect.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+# This runs ucs-detect with the same settings consistently so we can
+# compare our results over time. This is based on:
+# https://github.com/jquast/ucs-detect/blob/2958b7766783c92b3aad6a55e1e752cbe07ccaf3/data/ghostty.yaml
+ucs-detect \
+  --limit-codepoints=5000 \
+  --limit-words=5000 \
+  --limit-errors=1000 \
+  --quick=false \
+  --stream=stderr