feat: support npm resolution for file imports

.changeset/long-starfishes-mate.md

@@ -0,0 +1,19 @@
+---
+"wrangler": patch
+---
+
+feat: resolve npm exports for file imports
+
+Previously, when using wasm (or other static files) from an npm package, you would have to import the file like so:
+
+```js
+import wasm from "../../node_modules/svg2png-wasm/svg2png_wasm_bg.wasm";
+```
+
+This update now allows you to import the file like so, assuming it's exposed and available in the package's `exports` field:
+
+```js
+import wasm from "svg2png-wasm/svg2png_wasm_bg.wasm";
+```
+
+This will look at the package's `exports` field in `package.json` and resolve the file using [`resolve.exports`](https://www.npmjs.com/package/resolve.exports).

packages/wrangler/package.json

@@ -110,6 +110,7 @@
 		"miniflare": "3.20231002.1",
 		"nanoid": "^3.3.3",
 		"path-to-regexp": "^6.2.0",
+		"resolve.exports": "^2.0.2",
 		"selfsigned": "^2.0.1",
 		"source-map": "0.6.1",
 		"source-map-support": "0.5.21",

packages/wrangler/src/deployment-bundle/module-collection.ts

@@ -3,6 +3,7 @@
 import { readFile } from "node:fs/promises";
 import path from "node:path";
 import globToRegExp from "glob-to-regexp";
+import { exports as resolveExports } from "resolve.exports";
 import { logger } from "../logger";
 import {
 	findAdditionalModules,
@@ -237,7 +238,7 @@
 								// take the file and massage it to a
 								// transportable/manageable format
 
-								const filePath = path.join(args.resolveDir, args.path);
+								let filePath = path.join(args.resolveDir, args.path);
 
 								// If this was a found additional module, mark it as external.
 								// Note, there's no need to watch the file here as we already
@@ -251,6 +252,42 @@
 								// it to `esbuild` to bundle it.
 								if (isJavaScriptModuleRule(rule)) return;
 
+								// Check if this file is possibly from an npm package
+								// and if so, validate the import against the package.json exports
+								// and resolve the file path to the correct file.
+								if (args.path.includes("/") && !args.path.startsWith("./")) {
+									const dirName = path.dirname(args.path);
+									const packageJsonPath = path.join(
+										args.resolveDir,
+										"node_modules",
+										dirName,
+										"package.json"
+									);
+									// Try and read the npm package's package.json
+									// and then resolve the import against the package's exports
+									// and then finally override filePath if we find a match.
+									try {
+										const packageJson = JSON.parse(
+											await readFile(packageJsonPath, "utf8")
+										);
+										const testResolved = resolveExports(
+											packageJson,
+											args.path.replace(`${dirName}/`, "")
+										);
+										if (testResolved) {
+											filePath = path.join(
+												args.resolveDir,
+												"node_modules",
+												dirName,
+												testResolved[0]
+											);
+										}
+									} catch (e) {
+										// We tried, now it'll just fall-through to the previous behaviour
+										// and ENOENT if the absolute file path doesn't exist.
+									}
+								}
+
 								const fileContent = await readFile(filePath);
 								const fileHash = crypto
 									.createHash("sha1")