Make the component installable as a git dependency

`component/package.json` describes the built component as a package
(`@element-hq/element-call-component`: entry, stylesheet subpath, types,
peer dependencies) so that a host can depend on
`github:element-hq/element-call#<ref>&path:/component`. Its `prepare`
script builds on install, since nothing is published yet.

For that the component build now lands in `component/dist` instead of the
repository's `dist`, and `pnpm build:component` also emits the type
declarations (`component/tsconfig.build.json`, `build:component:types`),
which previously had to be produced by hand.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

README.md

@@ -217,7 +217,8 @@ See also:
 
 Element Call can also be embedded directly into another React application
 rather than being loaded in an iframe as a widget. `pnpm build:component`
-builds it as a library, and
+builds it as a library into `component/dist` (the bundle, its stylesheet and
+type declarations), and
 
 ```sh
 pnpm dev:component
@@ -240,6 +241,20 @@ what is inside it, with `html`, `body` and `:root` standing for that root (see
 `component/build/scopeStylesToRoot.ts`). A host's own page keeps its styles,
 and Element Call brings its own fonts and design tokens along.
 
+The package is not published yet. A host installs it as a git dependency on the
+`component` directory of this repository,
+
+```json
+"@element-hq/element-call-component": "github:element-hq/element-call#main&path:/component"
+```
+
+whose `prepare` script runs the build on install (the host's pnpm has to allow
+that: `allowBuilds` in its `pnpm-workspace.yaml`). It imports the component from
+`@element-hq/element-call-component` and the stylesheet from
+`@element-hq/element-call-component/style.css`, and has to provide `react`,
+`react-dom`, `matrix-js-sdk` and `livekit-client` itself, since the bundle leaves
+them external.
+
 ### Backend
 
 A docker compose file `docker-compose-dev.yml` is provided to start the

component/package.json

@@ -0,0 +1,42 @@
+{
+  "name": "@element-hq/element-call-component",
+  "version": "0.0.0",
+  "description": "Element Call as a React component. Consumed straight from the repository as a git dependency (github:element-hq/element-call#<ref>&path:/component): the host's package manager runs `prepare`, which builds `dist/`.",
+  "license": "SEE LICENSE IN ../README.md",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/element-hq/element-call",
+    "directory": "component"
+  },
+  "type": "module",
+  "devEngines": {
+    "packageManager": {
+      "name": "pnpm"
+    }
+  },
+  "files": [
+    "dist"
+  ],
+  "main": "./dist/element-call.js",
+  "module": "./dist/element-call.js",
+  "types": "./dist/types/component/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./dist/types/component/index.d.ts",
+      "default": "./dist/element-call.js"
+    },
+    "./style.css": "./dist/element-call.css"
+  },
+  "sideEffects": [
+    "*.css"
+  ],
+  "scripts": {
+    "prepare": "cd .. && pnpm install --frozen-lockfile && pnpm build:component"
+  },
+  "peerDependencies": {
+    "livekit-client": "^2.18.1",
+    "matrix-js-sdk": "*",
+    "react": "^19",
+    "react-dom": "^19"
+  }
+}

component/pnpm-lock.yaml

@@ -0,0 +1,9 @@
+lockfileVersion: '9.0'
+
+settings:
+  autoInstallPeers: false
+  excludeLinksFromLockfile: false
+
+importers:
+
+  .: {}

component/pnpm-workspace.yaml

@@ -0,0 +1,14 @@
+# Makes `component/` a pnpm project of its own rather than a directory inside
+# the repository's workspace. That matters when a host installs the component
+# straight from this repository (`github:element-hq/element-call#…&path:/component`):
+# pnpm prepares such a dependency by running `pnpm install` in this directory,
+# and only a project root gets its `prepare` script (see package.json) run, which
+# is what builds `dist/`. Inside the repository's own workspace the install
+# would silently target the repository instead and build nothing.
+#
+# Consequence for development: pnpm commands run from within this directory see
+# this project, not the repository; run them from the repository root.
+
+# Nothing to install here: the peers in package.json are the host's, and the
+# build runs against the repository's own node_modules (see `prepare`).
+autoInstallPeers: false

component/tsconfig.build.json

@@ -0,0 +1,20 @@
+{
+  // Declaration output for the component package (`pnpm build:component:types`).
+  // The root tsconfig only type-checks; this one emits `.d.ts` files, and nothing
+  // else, for everything the component's entry point reaches. The layout under
+  // `dist/types` mirrors the repository (`component/index.d.ts`, `src/…`), which
+  // is what `package.json` points its `types` at.
+  "extends": "../tsconfig.json",
+  "compilerOptions": {
+    "noEmit": false,
+    "emitDeclarationOnly": true,
+    "declaration": true,
+    "declarationMap": false,
+    "rootDir": "..",
+    "outDir": "./dist/types"
+  },
+  // The entry point, plus the ambient declarations (CSS modules, `?react` SVGs,
+  // `import.meta.env`, …) that the sources it reaches rely on.
+  "include": ["./index.tsx", "../src/@types/*.d.ts"],
+  "exclude": []
+}

package.json

@@ -17,9 +17,11 @@
     "build:sdk:development": "pnpm build:sdk --mode development",
     "build:sdk": "pnpm build:full --config vite-sdk.config.js",
     "build:sdk:production": "pnpm build:sdk",
-    "build:component": "pnpm build:full --config vite-component.config.js",
+    "build:component": "pnpm build:component:js && pnpm build:component:types",
+    "build:component:js": "pnpm build:full --config vite-component.config.js",
+    "build:component:types": "tsc -p component/tsconfig.build.json",
     "build:component:production": "pnpm build:component",
-    "build:component:development": "pnpm build:component --mode development",
+    "build:component:development": "pnpm build:component:js --mode development && pnpm build:component:types",
     "serve": "vite preview",
     "format": "oxfmt",
     "format:check": "oxfmt --check; rc=$?; [[ $rc -ne 0 ]] && printf '\\033[46;30m INFO \\033[0m To fix, run: pnpm format\\n' >&2; exit $rc",

vite-component.config.ts

@@ -38,6 +38,10 @@ export default defineConfig(({ mode }) => {
     // confined to the element Element Call is mounted in
     css: { postcss: { plugins: [scopeStylesToRoot()] } },
     build: {
+      // Into the package directory, so that `component/package.json` describes
+      // what sits next to it and the directory can be installed as a package
+      // (see its `files` and `exports`).
+      outDir: "component/dist",
       minify: mode === "production",
       sourcemap: true,
       // One stylesheet rather than one per chunk, so a host has a single file to