populate lastModified on update (#1290)

Author: mbostock

src/client/stdlib/fileAttachment.js

@@ -23,9 +23,11 @@ async function remote_fetch(file) {
 
 export class AbstractFile {
   constructor(name, mimeType = "application/octet-stream", lastModified) {
-    Object.defineProperty(this, "name", {value: `${name}`, enumerable: true});
-    Object.defineProperty(this, "mimeType", {value: `${mimeType}`, enumerable: true});
-    if (lastModified !== undefined) Object.defineProperty(this, "lastModified", {value: Number(lastModified), enumerable: true}); // prettier-ignore
+    Object.defineProperties(this, {
+      name: {value: `${name}`, enumerable: true},
+      mimeType: {value: `${mimeType}`, enumerable: true},
+      lastModified: {value: +lastModified, enumerable: true}
+    });
   }
   async blob() {
     return (await remote_fetch(this)).blob();

src/preview.ts

@@ -15,6 +15,7 @@ import type {WebSocket} from "ws";
 import {WebSocketServer} from "ws";
 import type {Config} from "./config.js";
 import {readConfig} from "./config.js";
+import type {LoaderResolver} from "./dataloader.js";
 import {HttpError, isEnoent, isHttpError, isSystemError} from "./error.js";
 import {getClientPath} from "./files.js";
 import type {FileWatchers} from "./fileWatchers.js";
@@ -23,7 +24,7 @@ import {transpileJavaScript, transpileModule} from "./javascript/transpile.js";
 import {parseMarkdown} from "./markdown.js";
 import type {MarkdownCode, MarkdownPage} from "./markdown.js";
 import {populateNpmCache} from "./npm.js";
-import {isPathImport} from "./path.js";
+import {isPathImport, resolvePath} from "./path.js";
 import {renderPage} from "./render.js";
 import type {Resolvers} from "./resolvers.js";
 import {getResolvers} from "./resolvers.js";
@@ -346,7 +347,7 @@ function handleWatch(socket: WebSocket, req: IncomingMessage, configPromise: Pro
           type: "update",
           html: diffHtml(previousHtml, html),
           code: diffCode(previousCode, code),
-          files: diffFiles(previousFiles, files),
+          files: diffFiles(previousFiles, files, getLastModifiedResolver(loaders, path)),
           tables: diffTables(previousTables, tables, previousFiles, files),
           stylesheets: diffStylesheets(previousStylesheets, stylesheets),
           hash: {previous: previousHash, current: hash}
@@ -467,10 +468,14 @@ function diffCode(oldCode: Map<string, string>, newCode: Map<string, string>): C
   return patch;
 }
 
-type FileDeclaration = {name: string; mimeType?: string; path: string};
+type FileDeclaration = {name: string; mimeType: string; lastModified: number; path: string};
 type FilePatch = {removed: string[]; added: FileDeclaration[]};
 
-function diffFiles(oldFiles: Map<string, string>, newFiles: Map<string, string>): FilePatch {
+function diffFiles(
+  oldFiles: Map<string, string>,
+  newFiles: Map<string, string>,
+  getLastModified: (name: string) => number | undefined
+): FilePatch {
   const patch: FilePatch = {removed: [], added: []};
   for (const [name, path] of oldFiles) {
     if (newFiles.get(name) !== path) {
@@ -479,12 +484,21 @@ function diffFiles(oldFiles: Map<string, string>, newFiles: Map<string, string>)
   }
   for (const [name, path] of newFiles) {
     if (oldFiles.get(name) !== path) {
-      patch.added.push({name, mimeType: mime.getType(name) ?? undefined, path});
+      patch.added.push({
+        name,
+        mimeType: mime.getType(name) ?? "application/octet-stream",
+        lastModified: getLastModified(name) ?? NaN,
+        path
+      });
     }
   }
   return patch;
 }
 
+function getLastModifiedResolver(loaders: LoaderResolver, path: string): (name: string) => number | undefined {
+  return (name) => loaders.getSourceLastModified(resolvePath(path, name));
+}
+
 type TableDeclaration = {name: string; path: string};
 type TablePatch = {removed: string[]; added: TableDeclaration[]};