build(theme-studio): add a local Makefile; root delegates test + coverage

theme-studio is a self-contained Python + JS subproject with its own toolchain (python3, node, uvx, headless Chrome), unrelated to the root Makefile's Elisp/ERT world. Gave it a local Makefile that owns that toolchain — test, check (fast, no browser), coverage, gen, open — so the build logic lives with the code and the short target names don't collide with the root's Elisp-flavored test/coverage.

The root keeps the discoverable entry points: theme-studio-test and a new theme-studio-coverage now delegate via make -C. run-tests.sh grows a --no-browser flag so `make check` can skip the headless-Chrome gates for a fast inner loop. gen/open take an optional SEED to view a specific palette.

coverage reports both halves: node --experimental-test-coverage for the three JS modules (all 100% line, ~96% branch) and uvx coverage for generate.py (89% lines; the rest is the __main__ writer and the optional seed-env branch).

2 files changed, 68 insertions, 1 deletions

diff --git a/scripts/theme-studio/Makefile b/scripts/theme-studio/Makefile
new file mode 100644
index 00000000..a7455b3d
--- /dev/null
+++ b/scripts/theme-studio/Makefile
@@ -0,0 +1,61 @@
+# Makefile for the theme-studio tool — a self-contained Python + JS subproject.
+# Its toolchain (python3, node, uvx, headless Chrome) is independent of the repo
+# root's Elisp/ERT world, so the build logic lives here with the code. The root
+# Makefile delegates: `make theme-studio-test` and `make theme-studio-coverage`
+# call `make -C scripts/theme-studio ...`.
+#
+# Recipes run in this directory, so the relative paths below resolve whether you
+# `cd` here or invoke via the root's `-C` delegation.
+
+# Absolute path to this directory (for `open`, which hands Chrome a file path).
+HERE := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
+
+# Optional palette seed for `gen` / `open`: make gen SEED=dupre.json
+SEED ?=
+
+.PHONY: help test check coverage gen open
+
+.DEFAULT_GOAL := help
+
+help:
+	@echo "theme-studio targets:"
+	@echo "  make test                - Full suite: Python + Node + browser hash gates"
+	@echo "  make check               - Fast gate: regenerate + Python + Node (no browser)"
+	@echo "  make coverage            - JS (node) + generate.py (uvx coverage) numbers"
+	@echo "  make gen [SEED=x.json]   - Regenerate theme-studio.html (optionally from a seed)"
+	@echo "  make open [SEED=x.json]  - Regenerate and open the page in Chrome"
+
+test:
+	@./run-tests.sh
+
+check:
+	@./run-tests.sh --no-browser
+
+coverage:
+	@echo "== JS coverage (node --experimental-test-coverage) =="
+	@node --test --experimental-test-coverage ./*.mjs 2>/dev/null \
+		| sed -n '/start of coverage report/,/end of coverage report/p'
+	@echo ""
+	@echo "== generate.py coverage =="
+	@if command -v uvx >/dev/null 2>&1; then \
+		uvx coverage run --include='generate.py' -m unittest test_generate >/dev/null 2>&1; \
+		uvx coverage report -m; \
+		uvx coverage erase >/dev/null 2>&1; \
+	else \
+		echo "uvx not found — skipping generate.py line coverage"; \
+		echo "($$(grep -c 'def test_' test_generate.py) test_generate.py tests exist)"; \
+	fi
+
+gen:
+	@THEME_STUDIO_SEED="$(SEED)" python3 generate.py
+
+open: gen
+	@c=""; for b in google-chrome-stable google-chrome chromium chromium-browser; do \
+		command -v $$b >/dev/null 2>&1 && { c=$$b; break; }; \
+	done; \
+	if [ -n "$$c" ]; then \
+		"$$c" "$(HERE)theme-studio.html" >/dev/null 2>&1 & \
+		echo "opened theme-studio.html in $$c"; \
+	else \
+		echo "no Chromium-family browser found"; exit 1; \
+	fi
diff --git a/scripts/theme-studio/run-tests.sh b/scripts/theme-studio/run-tests.sh
index d57f0044..42d24960 100755
--- a/scripts/theme-studio/run-tests.sh
+++ b/scripts/theme-studio/run-tests.sh
@@ -16,6 +16,10 @@ set -uo pipefail
 HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 cd "$HERE"
 
+# --no-browser skips the headless-Chrome hash gates for a fast inner loop.
+NO_BROWSER=0
+[ "${1:-}" = "--no-browser" ] && NO_BROWSER=1
+
 fail=0
 pass_msg() { printf '  PASS  %s\n' "$1"; }
 fail_msg() { printf '  FAIL  %s\n' "$1"; fail=1; }
@@ -50,7 +54,9 @@ for c in google-chrome-stable google-chrome chromium chromium-browser; do
   if command -v "$c" >/dev/null 2>&1; then CHROME="$c"; break; fi
 done
 HASHES="selftest cursortest readouttest deltatest oklchtest planetest locktest sorttest"
-if [ -z "$CHROME" ]; then
+if [ "$NO_BROWSER" = 1 ]; then
+  skip_msg "browser hash gates (--no-browser)"
+elif [ -z "$CHROME" ]; then
   for t in $HASHES; do skip_msg "#$t (no Chromium-family browser found)"; done
 else
   PROF="$(mktemp -d)"