page loaders

.gitignore

@@ -4,8 +4,6 @@
 /coverage/
 /dist/
 /docs/.observablehq/dist/
-/docs/theme/*.md
-/docs/themes.md
 /test/build/
 /test/output/**/*-changed.*
 /test/output/build/**/*-changed/

docs/[dir]/dynamic.md.js

@@ -0,0 +1,11 @@
+import {parseArgs} from "node:util";
+
+const {values} = parseArgs({
+  options: {
+    dir: {
+      type: "string"
+    }
+  }
+});
+
+console.log(JSON.stringify(values));

docs/dynamic.md.js

@@ -0,0 +1 @@
+console.log(Date.now());

observablehq.config.ts

@@ -2,6 +2,7 @@ import {existsSync} from "node:fs";
 import {readFile, readdir, stat} from "node:fs/promises";
 import {join} from "node:path/posix";
 import {formatPrefix} from "d3-format";
+import {themes} from "./docs/themes.md.ts";
 
 let stargazers_count: number;
 try {
@@ -86,7 +87,17 @@ export default {
     {name: "Converting notebooks", path: "/convert"},
     {name: "Contributing", path: "/contributing", pager: false}
   ],
-  paths: ["/foo/index", "/bar/index"],
+  paths: [
+    "/theme/dark",
+    "/theme/dark-alt",
+    "/theme/dashboard",
+    "/theme/light",
+    "/theme/light-alt",
+    "/theme/wide",
+    "/themes",
+    ...themes.dark.map((theme) => `/theme/${theme}`),
+    ...themes.light.map((theme) => `/theme/${theme}`)
+  ],
   base: "/framework",
   globalStylesheets: [
     "https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=Spline+Sans+Mono:ital,wght@0,300..700;1,300..700&display=swap"

package.json

@@ -19,10 +19,9 @@
     "observable": "dist/bin/observable.js"
   },
   "scripts": {
-    "dev": "rimraf --glob docs/themes.md docs/theme/*.md && (tsx watch docs/theme/generate-themes.ts & tsx watch --ignore docs --no-warnings=ExperimentalWarning ./src/bin/observable.ts preview --no-open)",
-    "docs:themes": "rimraf --glob docs/themes.md docs/theme/*.md && tsx docs/theme/generate-themes.ts",
-    "docs:build": "yarn docs:themes && tsx --no-warnings=ExperimentalWarning ./src/bin/observable.ts build",
-    "docs:deploy": "yarn docs:themes && tsx --no-warnings=ExperimentalWarning ./src/bin/observable.ts deploy",
+    "dev": "tsx watch --ignore docs --no-warnings=ExperimentalWarning ./src/bin/observable.ts preview --no-open",
+    "docs:build": "tsx --no-warnings=ExperimentalWarning ./src/bin/observable.ts build",
+    "docs:deploy": "tsx --no-warnings=ExperimentalWarning ./src/bin/observable.ts deploy",
     "build": "rimraf dist && node build.js --outdir=dist --outbase=src \"src/**/*.{ts,js,css}\" --ignore \"**/*.d.ts\"",
     "test": "concurrently npm:test:mocha npm:test:tsc npm:test:lint npm:test:prettier",
     "test:coverage": "c8 --check-coverage --lines 80 --per-file yarn test:mocha",

src/build.ts

@@ -17,7 +17,6 @@ import {getModuleResolver, getResolvers} from "./resolvers.js";
 import {resolveImportPath, resolveStylesheetPath} from "./resolvers.js";
 import {bundleStyles, rollupClient} from "./rollup.js";
 import type {Params} from "./route.js";
-import {find} from "./route.js";
 import {searchIndex} from "./search.js";
 import {Telemetry} from "./telemetry.js";
 import {tree} from "./tree.js";
@@ -83,9 +82,10 @@ export async function build(
   const globalImports = new Set<string>(); // e.g., "/_observablehq/search.js"
   const stylesheets = new Set<string>(); // e.g., "/style.css"
   for (const path of paths.map(normalizePagePath)) {
-    const found = find(root, `${path}.md`);
-    if (!found) throw new Error(`page not found: ${path}`);
-    const {path: sourceFile, params} = found;
+    const loader = loaders.find(`${path}.md`);
+    if (!loader) throw new Error(`page not found: ${path}`);
+    const {params} = loader;
+    const sourceFile = await loader.load(effects);
     const sourcePath = join(root, sourceFile);
     const options = {...config, params, path};
     effects.output.write(`${faint("parse")} ${sourcePath} `);
@@ -96,7 +96,7 @@ export async function build(
       effects.logger.log(faint("(skipped)"));
       continue;
     }
-    const resolvers = await getResolvers(page, {path: sourceFile, ...config});
+    const resolvers = await getResolvers(page, {path, ...config});
     const elapsed = Math.floor(performance.now() - start);
     for (const f of resolvers.assets) files.add(resolvePath(path, f));
     for (const f of resolvers.files) files.add(resolvePath(path, f));
@@ -173,23 +173,19 @@ export async function build(
 
   // Copy over referenced files, accumulating hashed aliases.
   for (const file of files) {
-    let sourcePath: string;
     effects.output.write(`${faint("copy")} ${join(root, file)} ${faint("→")} `);
     const loader = loaders.find(join("/", file), {useStale: true});
     if (!loader) {
       effects.logger.error(red("error: missing referenced file"));
       continue;
     }
-    if ("load" in loader) {
-      try {
-        sourcePath = join(root, await loader.load(effects));
-      } catch (error) {
-        if (!isEnoent(error)) throw error;
-        effects.logger.error(red("error: missing referenced file"));
-        continue;
-      }
-    } else {
-      sourcePath = loader.path;
+    let sourcePath: string;
+    try {
+      sourcePath = join(root, await loader.load(effects));
+    } catch (error) {
+      if (!isEnoent(error)) throw error;
+      effects.logger.error(red("error: missing referenced file"));
+      continue;
     }
     const contents = await readFile(sourcePath);
     const hash = createHash("sha256").update(contents).digest("hex").slice(0, 8);