annotate local paths

docs/annotate.js

@@ -0,0 +1,17 @@
+import {FileAttachment} from "observablehq:stdlib";
+
+// Framework’s FileAttachment
+FileAttachment("./lib/miserables.json").json();
+
+// Static ESM imports
+import {foo, bar} from "./foo.js";
+
+import {Chart} from "./chart.js";
+
+// Dynamic ESM imports
+const {Chart: c} = await import("./chart.js");
+
+// import.meta.resolve
+const chartHelperURL = import.meta.resolve("./chart.js");
+
+console.warn({foo, bar, Chart, c, chartHelperURL});

observablehq.config.ts

@@ -97,6 +97,7 @@ export default {
   ],
   dynamicPaths: [
     "/chart.js",
+    "/annotate.js",
     "/theme/dark",
     "/theme/dark-alt",
     "/theme/dashboard",

src/javascript/transpile.ts

@@ -101,7 +101,7 @@ export async function transpileModule(
 
   async function rewriteImportSource(source: StringLiteral) {
     const specifier = getStringLiteralValue(source);
-    output.replaceLeft(source.start, source.end, JSON.stringify(await resolveImport(specifier)));
+    output.replaceLeft(source.start, source.end, annotatePath(await resolveImport(specifier)));
   }
 
   for (const {name, node} of findFiles(body, path, input)) {
@@ -111,17 +111,16 @@ export async function transpileModule(
     output.replaceLeft(
       source.start,
       source.end,
-      `${JSON.stringify(
+      `${
         info
-          ? {
-              name: p,
-              mimeType: mime.getType(name) ?? undefined,
-              path: relativePath(servePath, resolveFile(name)),
-              lastModified: info.mtimeMs,
-              size: info.size
-            }
-          : p
-      )}, import.meta.url`
+          ? `{
+              name: ${JSON.stringify(p)},
+              mimeType: ${JSON.stringify(mime.getType(name) ?? undefined)},
+              path: ${annotatePath(relativePath(servePath, resolveFile(name)))},
+              lastModified: ${JSON.stringify(info.mtimeMs)},
+              size: ${JSON.stringify(info.size)}`
+          : JSON.stringify(p)
+      }, import.meta.url`
     );
   }
 
@@ -137,7 +136,7 @@ export async function transpileModule(
     if (isImportMetaResolve(node) && isStringLiteral(source)) {
       const value = getStringLiteralValue(source);
       const resolution = isPathImport(value) && !isJavaScript(value) ? resolveFile(value) : await resolveImport(value);
-      output.replaceLeft(source.start, source.end, JSON.stringify(resolution));
+      output.replaceLeft(source.start, source.end, annotatePath(resolution));
     }
   }
 
@@ -159,7 +158,7 @@ function rewriteImportExpressions(
   resolveFile: (specifier: string) => string = String
 ): void {
   function rewriteImportSource(source: StringLiteral) {
-    output.replaceLeft(source.start, source.end, JSON.stringify(resolveImport(getStringLiteralValue(source))));
+    output.replaceLeft(source.start, source.end, annotatePath(resolveImport(getStringLiteralValue(source))));
   }
   simple(body, {
     ImportExpression(node) {
@@ -176,9 +175,7 @@ function rewriteImportExpressions(
         output.replaceLeft(
           node.start,
           node.end,
-          isPathImport(resolution)
-            ? `new URL(${JSON.stringify(resolution)}, location).href`
-            : JSON.stringify(resolution)
+          isPathImport(resolution) ? `new URL(${annotatePath(resolution)}, location).href` : JSON.stringify(resolution)
         );
       }
     }
@@ -205,7 +202,7 @@ function rewriteImportDeclarations(
   for (const node of declarations) {
     output.delete(node.start, node.end + +(output.input[node.end] === "\n"));
     specifiers.push(rewriteImportSpecifiers(node));
-    imports.push(`import(${JSON.stringify(resolve(getStringLiteralValue(node.source as StringLiteral)))})`);
+    imports.push(`import(${annotatePath(resolve(getStringLiteralValue(node.source as StringLiteral)))})`);
   }
   if (declarations.length > 1) {
     output.insertLeft(0, `const [${specifiers.join(", ")}] = await Promise.all([${imports.join(", ")}]);\n`);
@@ -259,3 +256,12 @@ export function rewriteParams(output: Sourcemap, body: Node, params: Params, inp
     output.replaceLeft(node.start, node.end, JSON.stringify(params[name]));
   }
 }
+
+/**
+ * Annotate a path to a local import or file so it can be reworked server-side.
+ */
+function annotatePath(uri: string): string {
+  return !uri.startsWith(".") || /(?:[.][/]|(?:[.][.][/])+)(_jsr|_node|_npm|_observablehq)[/]/.test(uri)
+    ? JSON.stringify(uri)
+    : (console.warn(`/* 👉 */${JSON.stringify(uri)}/* 👈 */`), `/* 👉 */${JSON.stringify(uri)}/* 👈 */`);
+}