parse import assertions

declarations/WebpackOptions.d.ts

@@ -1316,6 +1316,10 @@ export interface ModuleOptions {
  * A rule description with conditions and effects for modules.
  */
 export interface RuleSetRule {
+	/**
+	 * Specify assertions on the imported module. If one of the assertion can't be met, the module will fail to import.
+	 */
+	assert?: ImportAssertions;
 	/**
 	 * Match the child compiler name.
 	 */
@@ -1427,6 +1431,15 @@ export interface RuleSetRule {
 	 */
 	use?: RuleSetUse;
 }
+/**
+ * Specify assertions on the imported module. If one of the assertion can't be met, the module will fail to import.
+ */
+export interface ImportAssertions {
+	/**
+	 * The module type.
+	 */
+	type?: "json";
+}
 /**
  * Logic operators used in a condition matcher.
  */

lib/NormalModuleFactory.js

@@ -44,6 +44,7 @@ const { parseResource } = require("./util/identifier");
  * @property {ModuleFactoryCreateData["resolveOptions"]} resolveOptions
  * @property {string} context
  * @property {string} request
+ * @property {Map} assertions
  * @property {ModuleDependency[]} dependencies
  * @property {Object} createData
  * @property {LazySet<string>} fileDependencies
@@ -189,6 +190,7 @@ const ruleSetCompiler = new RuleSetCompiler([
 	new BasicEffectRulePlugin("resolve"),
 	new BasicEffectRulePlugin("generator"),
 	new BasicEffectRulePlugin("layer"),
+	new BasicEffectRulePlugin("assert"),
 	new UseEffectRulePlugin()
 ]);
 
@@ -339,6 +341,7 @@ class NormalModuleFactory extends ModuleFactory {
 					context,
 					dependencies,
 					request,
+					assertions = new Map(),
 					resolveOptions,
 					fileDependencies,
 					missingDependencies,
@@ -514,6 +517,13 @@ class NormalModuleFactory extends ModuleFactory {
 							} else {
 								type = "javascript/auto";
 							}
+							if (assertions.has("type") && type !== assertions.get("type")) {
+								throw new Error(
+									`type mismatch; requested type ${assertions.get(
+										"type"
+									)} but got ${type}`
+								);
+							}
 						}
 						const resolveOptions = settings.resolve;
 						const layer = settings.layer;
@@ -694,6 +704,7 @@ class NormalModuleFactory extends ModuleFactory {
 		const resolveOptions = data.resolveOptions || EMPTY_RESOLVE_OPTIONS;
 		const dependency = dependencies[0];
 		const request = dependency.request;
+		const assertions = dependency.assertions;
 		const contextInfo = data.contextInfo;
 		const fileDependencies = new LazySet();
 		const missingDependencies = new LazySet();
@@ -704,6 +715,7 @@ class NormalModuleFactory extends ModuleFactory {
 			resolveOptions,
 			context,
 			request,
+			assertions,
 			dependencies,
 			fileDependencies,
 			missingDependencies,

lib/config/defaults.js

@@ -449,11 +449,13 @@ const applyModuleDefaults = (
 			},
 			{
 				test: /\.json$/i,
-				type: "json"
+				type: "json",
+				assert: { type: "json" }
 			},
 			{
 				mimetype: "application/json",
-				type: "json"
+				type: "json",
+				assert: { type: "json" }
 			},
 			{
 				test: /\.mjs$/i,

lib/dependencies/HarmonyImportDependency.js

@@ -32,8 +32,9 @@ class HarmonyImportDependency extends ModuleDependency {
 	 *
 	 * @param {string} request request string
 	 * @param {number} sourceOrder source order
+	 * @param {Map} assertions import assertions
 	 */
-	constructor(request, sourceOrder) {
+	constructor(request, sourceOrder, assertions = new Map()) {
 		super(request);
 		this.sourceOrder = sourceOrder;
 	}

lib/dependencies/HarmonyImportDependencyParserPlugin.js

@@ -31,6 +31,16 @@ const harmonySpecifierTag = Symbol("harmony import");
  * @property {boolean} await
  */
 
+function getAssertionMap(node) {
+	if (node.assertions === undefined) {
+		return new Map();
+	}
+	return node.assertions.reduce((map, assert) => {
+		map.set(assert.key.name, assert.value.value);
+		return map;
+	}, new Map());
+}
+
 module.exports = class HarmonyImportDependencyParserPlugin {
 	constructor(options) {
 		this.strictExportPresence = options.strictExportPresence;
@@ -65,9 +75,11 @@ module.exports = class HarmonyImportDependencyParserPlugin {
 				clearDep.loc = statement.loc;
 				parser.state.module.addPresentationalDependency(clearDep);
 				parser.unsetAsiPosition(statement.range[1]);
+				const asserts = getAssertionMap(statement);
 				const sideEffectDep = new HarmonyImportSideEffectDependency(
 					source,
-					parser.state.lastHarmonyImportOrder
+					parser.state.lastHarmonyImportOrder,
+					asserts
 				);
 				sideEffectDep.loc = statement.loc;
 				parser.state.module.addDependency(sideEffectDep);

lib/dependencies/HarmonyImportSideEffectDependency.js

@@ -20,8 +20,8 @@ const HarmonyImportDependency = require("./HarmonyImportDependency");
 /** @typedef {import("../util/runtime").RuntimeSpec} RuntimeSpec */
 
 class HarmonyImportSideEffectDependency extends HarmonyImportDependency {
-	constructor(request, sourceOrder) {
-		super(request, sourceOrder);
+	constructor(request, sourceOrder, assertions) {
+		super(request, sourceOrder, assertions);
 	}
 
 	get type() {

lib/dependencies/ModuleDependency.js

@@ -22,6 +22,7 @@ class ModuleDependency extends Dependency {
 		this.request = request;
 		this.userRequest = request;
 		this.range = undefined;
+		this.assertions = new Map();
 	}
 
 	/**

lib/javascript/JavascriptParser.js

@@ -6,6 +6,7 @@
 "use strict";
 
 const { Parser: AcornParser } = require("acorn");
+const { importAssertions } = require("acorn-import-assertions");
 const { SyncBailHook, HookMap } = require("tapable");
 const vm = require("vm");
 const Parser = require("../Parser");
@@ -61,7 +62,7 @@ const ALLOWED_MEMBER_TYPES_ALL = 0b11;
 
 // Syntax: https://developer.mozilla.org/en/SpiderMonkey/Parser_API
 
-const parser = AcornParser;
+const parser = AcornParser.extend(importAssertions);
 
 class VariableInfo {
 	/**

package.json

@@ -11,6 +11,7 @@
     "@webassemblyjs/wasm-edit": "1.11.1",
     "@webassemblyjs/wasm-parser": "1.11.1",
     "acorn": "^8.4.1",
+	"acorn-import-assertions": "^1.4.6",
     "browserslist": "^4.14.5",
     "chrome-trace-event": "^1.0.2",
     "enhanced-resolve": "^5.8.0",

schemas/WebpackOptions.json

@@ -1237,6 +1237,18 @@
       "description": "Wrap javascript code into IIFE's to avoid leaking into global scope.",
       "type": "boolean"
     },
+    "ImportAssertions": {
+      "description": "Specify assertions on the imported module. If one of the assertion can't be met, the module will fail to import.",
+      "type": "object",
+      "additionalProperties": false,
+      "properties": {
+        "type": {
+          "description": "The module type.",
+          "type": "string",
+          "enum": ["json"]
+        }
+      }
+    },
     "ImportFunctionName": {
       "description": "The name of the native import() function (can be exchanged for a polyfill).",
       "type": "string"
@@ -3585,6 +3597,15 @@
       "type": "object",
       "additionalProperties": false,
       "properties": {
+        "assert": {
+          "description": "Specify assertions on the imported module. If one of the assertion can't be met, the module will fail to import.",
+          "type": "object",
+          "oneOf": [
+            {
+              "$ref": "#/definitions/ImportAssertions"
+            }
+          ]
+        },
         "compiler": {
           "description": "Match the child compiler name.",
           "oneOf": [

test/Defaults.unittest.js

@@ -122,10 +122,16 @@ describe("Defaults", () => {
 		      Object {
 		        "test": /\\\\\\.json\\$/i,
 		        "type": "json",
+                "assert": Object {
+		          "type": "json",
+		        },
 		      },
 		      Object {
 		        "mimetype": "application/json",
 		        "type": "json",
+                "assert": Object {
+		          "type": "json",
+		        },
 		      },
 		      Object {
 		        "resolve": Object {

test/Validation.test.js

@@ -182,7 +182,7 @@ describe("Validation", () => {
 			expect(msg).toMatchInlineSnapshot(`
 			"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 			 - configuration.module.rules[0].oneOf[0] has an unknown property 'passer'. These properties are valid:
-			   object { compiler?, dependency?, descriptionData?, enforce?, exclude?, generator?, include?, issuer?, issuerLayer?, layer?, loader?, mimetype?, oneOf?, options?, parser?, realResource?, resolve?, resource?, resourceFragment?, resourceQuery?, rules?, scheme?, sideEffects?, test?, type?, use? }
+			   object { assert?, compiler?, dependency?, descriptionData?, enforce?, exclude?, generator?, include?, issuer?, issuerLayer?, layer?, loader?, mimetype?, oneOf?, options?, parser?, realResource?, resolve?, resource?, resourceFragment?, resourceQuery?, rules?, scheme?, sideEffects?, test?, type?, use? }
 			   -> A rule description with conditions and effects for modules."
 		`)
 	);

test/cases/json/data/poison.js

@@ -0,0 +1 @@
+throw new Error("imported")

test/cases/json/import-assertions-type-json/index.js

@@ -0,0 +1,5 @@
+import c from "../data/c.json" assert { type: "json" };
+
+it("should be possible to import json data with import assertion", function() {
+	expect(c[2]).toBe(3);
+});

types.d.ts

@@ -4361,6 +4361,16 @@ type IgnorePluginOptions =
 			 */
 			checkResource?: (resource: string, context: string) => boolean;
 	  };
+
+/**
+ * Specify assertions on the imported module. If one of the assertion can't be met, the module will fail to import.
+ */
+declare interface ImportAssertions {
+	/**
+	 * The module type.
+	 */
+	type?: "json";
+}
 declare interface ImportModuleOptions {
 	/**
 	 * the target layer
@@ -6372,6 +6382,7 @@ declare class ModuleDependency extends Dependency {
 	request: string;
 	userRequest: string;
 	range: any;
+	assertions: Map<any, any>;
 	static Template: typeof DependencyTemplate;
 	static NO_EXPORTS_REFERENCED: string[][];
 	static EXPORTS_OBJECT_REFERENCED: string[][];
@@ -8928,6 +8939,7 @@ declare interface ResolveData {
 	resolveOptions?: ResolveOptionsWebpackOptions;
 	context: string;
 	request: string;
+	assertions: Map<any, any>;
 	dependencies: ModuleDependency[];
 	createData: Object;
 	fileDependencies: LazySet<string>;
@@ -9339,6 +9351,11 @@ declare interface RuleSetLogicalConditionsAbsolute {
  * A rule description with conditions and effects for modules.
  */
 declare interface RuleSetRule {
+	/**
+	 * Specify assertions on the imported module. If one of the assertion can't be met, the module will fail to import.
+	 */
+	assert?: ImportAssertions;
+
 	/**
 	 * Match the child compiler name.
 	 */

yarn.lock

@@ -1225,6 +1225,11 @@ acorn-globals@^6.0.0:
     acorn "^7.1.1"
     acorn-walk "^7.1.1"
 
+acorn-import-assertions@^1.4.6:
+  version "1.4.6"
+  resolved "https://registry.yarnpkg.com/acorn-import-assertions/-/acorn-import-assertions-1.4.6.tgz#4c319605512950af5da82f4893ab8a087299fde2"
+  integrity sha512-wMx12i/IaRy3IyA4XzOhwgGzRRLa2Vhj30Pk99pqG2becPTV3ip/3ANM+4zrRilBs2JUTp3opRoIkxJ4f3II4g==
+
 acorn-jsx@^5.3.1:
   version "5.3.1"
   resolved "https://registry.yarnpkg.com/acorn-jsx/-/acorn-jsx-5.3.1.tgz#fc8661e11b7ac1539c47dbfea2e72b3af34d267b"