test(theme-studio): extract app-core.js and unit-test the app logic

The refactor's goal was to make the app logic testable; this realizes it. Pulled the pure package-face model and the dropdown option list into app-core.js — nameToHex, buildPkgmap, packagesForExport, mergePackagesInto, effResolve (the inherit-chain resolver behind pkgEffFg/pkgEffBg), and optList — with every dependency passed as a parameter so there is no DOM and no module-global reliance. generate.py inlines it into the page the same way it inlines colormath.js (strip exports, placeholder, integrity check), so the browser runs the same code the tests import.

app.js keeps thin wrappers (pname, seedPkgmap, ddList, pkgEffFg, pkgEffBg) that pass the live PALETTE / APPS / PKGMAP into the core, so no call site changed and the built DOM is byte-identical to before.

test-app-core.mjs adds 18 Normal/Boundary/Error tests over the extracted logic — name resolution, the seed/export/merge round trip, the inherit chain including a cycle that must terminate at null, and the "(gone)" dropdown entry — plus an inline-integrity check that the page carries the core verbatim. The node suite goes 25 to 43 tests; python templating gains the app-core integrity assertion.

1 files changed, 28 insertions, 0 deletions

diff --git a/scripts/theme-studio/app-core.js b/scripts/theme-studio/app-core.js
new file mode 100644
index 00000000..34fb8051
--- /dev/null
+++ b/scripts/theme-studio/app-core.js
@@ -0,0 +1,28 @@
+// Pure app logic — the package-face model and the dropdown option list — with no
+// DOM and no module globals (every dependency is a parameter). It is unit-tested
+// directly (test-app-core.mjs) and inlined into the page like colormath.js, so
+// the browser runs the same code the tests import. The app.js wrappers (pname,
+// seedPkgmap, ddList, pkgEffFg, pkgEffBg) are thin delegators that pass the
+// live PALETTE / APPS / PKGMAP into these.
+
+// Resolve a palette name (or a raw #hex) to a hex; null when the name is unknown.
+function nameToHex(n,palette){if(!n)return null;if(/^#/.test(n))return n;const p=palette.find(p=>p[1]===n);return p?p[0]:null;}
+
+// Seed the package-face map from the app inventory's per-face defaults.
+function buildPkgmap(apps,palette){const m={};for(const app in apps){m[app]={};for(const row of apps[app].faces){const face=row[0],d=row[2]||{};m[app][face]={fg:nameToHex(d.fg,palette),bg:nameToHex(d.bg,palette),bold:!!d.bold,italic:!!d.italic,underline:!!d.underline,strike:!!d.strike,inherit:d.inherit||null,height:d.height||1,source:'default'};}}return m;}
+
+// The package faces worth exporting (anything seeded or user-touched), trimmed.
+function packagesForExport(map){const out={};for(const app in map){const faces={};for(const face in map[app]){const f=map[app][face];if(f.source==='default'||f.source==='user'||f.source==='cleared'){const o={fg:f.fg,bg:f.bg,bold:f.bold,italic:f.italic,underline:!!f.underline,strike:!!f.strike,inherit:f.inherit,source:f.source};if(f.height&&f.height!==1)o.height=f.height;faces[face]=o;}}if(Object.keys(faces).length)out[app]=faces;}return out;}
+
+// Merge an imported package block into a face map, filling missing fields.
+function mergePackagesInto(map,pkgs){if(!pkgs)return;for(const app in pkgs){if(!map[app])map[app]={};for(const face in pkgs[app]){const f=pkgs[app][face]||{};map[app][face]={fg:f.fg??null,bg:f.bg??null,bold:!!f.bold,italic:!!f.italic,underline:!!f.underline,strike:!!f.strike,inherit:f.inherit??null,height:f.height||1,source:f.source||'user'};}}}
+
+// Effective fg/bg for a package face, following its inherit chain. seen guards
+// against an inherit cycle (returns null rather than recursing forever).
+function effResolve(map,app,face,attr,seen){seen=seen||{};const f=map[app]&&map[app][face];if(!f||seen[face])return null;seen[face]=1;if(f[attr])return f[attr];if(f.inherit&&map[app][f.inherit])return effResolve(map,app,f.inherit,attr,seen);return null;}
+
+// Standard swatch-dropdown option list: a default entry, then the palette. When
+// cur is set but no longer in the palette, surface it as a "(gone)" entry first.
+function optList(cur,palette){const have=cur===''||palette.some(p=>p[0]===cur);return [['','— default —'],...(have?palette:[[cur,'(gone) '+cur],...palette])];}
+
+export { nameToHex, buildPkgmap, packagesForExport, mergePackagesInto, effResolve, optList };