json / wasm import assertion support.

dist-raw/node-options.js

@@ -34,7 +34,9 @@ function parseArgv(argv) {
     '--es-module-specifier-resolution': '--experimental-specifier-resolution',
     '--experimental-policy': String,
     '--conditions': [String],
-    '--pending-deprecation': Boolean
+    '--pending-deprecation': Boolean,
+    '--experimental-json-modules': Boolean,
+    '--experimental-wasm-modules': Boolean,
   }, {
     argv,
     permissive: true

src/esm.ts

@@ -67,7 +67,10 @@ export namespace NodeLoaderHooksAPI2 {
   ) => Promise<{ url: string }>;
   export type LoadHook = (
     url: string,
-    context: { format: NodeLoaderHooksFormat | null | undefined },
+    context: {
+      format: NodeLoaderHooksFormat | null | undefined;
+      importAssertions?: NodeImportAssertions;
+    },
     defaultLoad: NodeLoaderHooksAPI2['load']
   ) => Promise<{
     format: NodeLoaderHooksFormat;
@@ -83,6 +86,10 @@ export type NodeLoaderHooksFormat =
   | 'module'
   | 'wasm';
 
+export type NodeImportAssertions = {
+  type: 'json' | 'wasm';
+};
+
 /** @internal */
 export function registerAndCreateEsmHooks(opts?: RegisterOptions) {
   // Automatically performs registration just like `-r ts-node/register`
@@ -159,7 +166,10 @@ export function createEsmHooks(tsNodeService: Service) {
   // `load` from new loader hook API (See description at the top of this file)
   async function load(
     url: string,
-    context: { format: NodeLoaderHooksFormat | null | undefined },
+    context: {
+      format: NodeLoaderHooksFormat | null | undefined;
+      importAssertions?: NodeImportAssertions;
+    },
     defaultLoad: typeof load
   ): Promise<{
     format: NodeLoaderHooksFormat;
@@ -176,7 +186,10 @@ export function createEsmHooks(tsNodeService: Service) {
       // Call the new defaultLoad() to get the source
       const { source: rawSource } = await defaultLoad(
         url,
-        { format },
+        {
+          format,
+          importAssertions: context.importAssertions,
+        },
         defaultLoad
       );
 

tests/esm-import-assertions/car.json

@@ -0,0 +1,5 @@
+{
+  "color": "fuchsia",
+  "doors": "open",
+  "seats": 2
+}

tests/esm-import-assertions/importJson.ts

@@ -0,0 +1,14 @@
+import carData from './car.json' assert { type: 'json' };
+
+if (carData.color !== 'fuchsia') throw new Error('failed to import json');
+
+const { default: dynamicCarData } = await import('./car.json', {
+  assert: { type: 'json' },
+});
+
+if (dynamicCarData.doors !== 'open')
+  throw new Error('failed to dynamically import json');
+
+console.log(
+  `A ${carData.color} car has ${carData.seats} seats and the doors are ${dynamicCarData.doors}.`
+);

tests/esm-import-assertions/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

tests/esm-import-assertions/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "module": "ESNext",
+    "target": "ESNext",
+    "resolveJsonModule": true,
+    "allowJs": true,
+    "moduleResolution": "node",
+    "allowSyntheticDefaultImports": true
+  }
+}