Move WASM building to onLoad

We don't want to use onResolve because we can resolve the same WASM
multiple times (i.e. multiple files importing the same WASM), leading to
the WASM being built multiple times, possibly in parallel (which may
lead to build failure).

packages/tuta-wasm-loader/lib/index.ts

@@ -99,6 +99,7 @@ function createOutputFolderStructure(output: string) {
 export function esbuildWasmLoader(options: PluginOptions) {
 	const normalizedOptions = parseOptions(options)
 	const fallbackOptions = normalizedOptions.fallback
+
 	return {
 		name: "wasm",
 		setup(build: PluginBuild) {
@@ -112,15 +113,11 @@ export function esbuildWasmLoader(options: PluginOptions) {
 						path: args.path.replaceAll("wasm-fallback:", ""),
 						namespace: "wasm-fallback",
 					}
-				}
-
-				const lib = findLib(normalizedOptions, args.path)
-
-				await generateWasm(lib.command, lib)
-
-				return {
-					path: path.join("wasm", args.path),
-					namespace: "wasm-loader",
+				} else {
+					return {
+						path: path.join("wasm", args.path),
+						namespace: "wasm-loader",
+					}
 				}
 			})
 
@@ -134,6 +131,13 @@ export function esbuildWasmLoader(options: PluginOptions) {
 				})
 			}
 
+			build.onLoad({ filter: /\.wasm$/ }, async (args): Promise<OnLoadResult | undefined> => {
+				const lib = findLib(normalizedOptions, path.basename(args.path))
+				await generateWasm(lib.command, lib)
+				// don't try to read the wasm since we use wasm-loader or wasm-fallback to use the wasm
+				return undefined
+			})
+
 			build.onLoad({ filter: /.*/, namespace: "wasm-loader" }, async (args): Promise<OnLoadResult> => {
 				return {
 					contents: await generateImportCode(args.path, fallbackOptions != null),
@@ -152,6 +156,7 @@ export function esbuildWasmLoader(options: PluginOptions) {
 					}
 				})
 			}
+
 			build.onResolve({ filter: /node:*/, namespace: "wasm-loader" }, async (_) => {
 				return {
 					external: true,