refactor ModuleGraph to use internal dependency

lib/ModuleGraph.js

@@ -30,9 +30,20 @@ class ModuleGraphModule {
 	}
 }
 
+class ModuleGraphDependency {
+	constructor() {
+		/** @type {ModuleGraphConnection} */
+		this.connection = undefined;
+		/** @type {Module} */
+		this.parentModule = undefined;
+		/** @type {DependenciesBlock} */
+		this.parentBlock = undefined;
+	}
+}
+
 class ModuleGraph {
 	constructor() {
-		/** @type {Map<Dependency, ModuleGraphConnection>} */
+		/** @type {Map<Dependency, ModuleGraphDependency>} */
 		this._dependencyMap = new Map();
 		/** @type {Map<Module, ModuleGraphModule>} */
 		this._moduleMap = new Map();
@@ -40,8 +51,6 @@ class ModuleGraph {
 		this._originMap = new Map();
 		/** @type {Map<any, Object>} */
 		this._metaMap = new Map();
-		/** @type {Map<Dependency, {module: Module, block: DependenciesBlock}>} */
-		this._parentsMap = new Map();
 	}
 
 	/**
@@ -57,6 +66,19 @@ class ModuleGraph {
 		return mgm;
 	}
 
+	/**
+	 * @param {Dependency} dependency the dependency
+	 * @returns {ModuleGraphDependency} the internal dependency
+	 */
+	_getModuleGraphDependency(dependency) {
+		let mgd = this._dependencyMap.get(dependency);
+		if (mgd === undefined) {
+			mgd = new ModuleGraphDependency();
+			this._dependencyMap.set(dependency, mgd);
+		}
+		return mgd;
+	}
+
 	/**
 	 * @param {Dependency} dependency the dependency
 	 * @param {DependenciesBlock} block parent block
@@ -64,7 +86,9 @@ class ModuleGraph {
 	 * @returns {void}
 	 */
 	setParents(dependency, block, module) {
-		this._parentsMap.set(dependency, { module, block });
+		const mgd = this._getModuleGraphDependency(dependency);
+		mgd.parentBlock = block;
+		mgd.parentModule = module;
 	}
 
 	/**
@@ -72,8 +96,8 @@ class ModuleGraph {
 	 * @returns {Module} parent module
 	 */
 	getParentModule(dependency) {
-		const entry = this._parentsMap.get(dependency);
-		return entry !== undefined ? entry.module : null;
+		const mgd = this._getModuleGraphDependency(dependency);
+		return mgd.parentModule;
 	}
 
 	/**
@@ -81,8 +105,8 @@ class ModuleGraph {
 	 * @returns {DependenciesBlock} parent block
 	 */
 	getParentBlock(dependency) {
-		const entry = this._parentsMap.get(dependency);
-		return entry !== undefined ? entry.block : null;
+		const mgd = this._getModuleGraphDependency(dependency);
+		return mgd.parentBlock;
 	}
 
 	/**
@@ -97,7 +121,8 @@ class ModuleGraph {
 			dependency,
 			module
 		);
-		this._dependencyMap.set(dependency, connection);
+		const mgd = this._getModuleGraphDependency(dependency);
+		mgd.connection = connection;
 		const connections = this._getModuleGraphModule(module).incomingConnections;
 		connections.add(connection);
 		const originConnections = this._getModuleGraphModule(originModule)
@@ -111,7 +136,7 @@ class ModuleGraph {
 	 * @returns {void}
 	 */
 	updateModule(dependency, module) {
-		const connection = this._dependencyMap.get(dependency);
+		const { connection } = this._getModuleGraphDependency(dependency);
 		if (connection.module === module) return;
 		const oldMgm = this._getModuleGraphModule(connection.module);
 		oldMgm.incomingConnections.delete(connection);
@@ -126,7 +151,7 @@ class ModuleGraph {
 	 * @returns {void}
 	 */
 	addExplanation(dependency, explanation) {
-		const connection = this._dependencyMap.get(dependency);
+		const { connection } = this._getModuleGraphDependency(dependency);
 		connection.addExplanation(explanation);
 	}
 
@@ -175,7 +200,7 @@ class ModuleGraph {
 	 * @returns {Module} the referenced module
 	 */
 	getResolvedModule(dependency) {
-		const connection = this._dependencyMap.get(dependency);
+		const { connection } = this._getModuleGraphDependency(dependency);
 		return connection !== undefined ? connection.resolvedModule : null;
 	}
 
@@ -184,7 +209,7 @@ class ModuleGraph {
 	 * @returns {ModuleGraphConnection | undefined} the connection
 	 */
 	getConnection(dependency) {
-		const connection = this._dependencyMap.get(dependency);
+		const { connection } = this._getModuleGraphDependency(dependency);
 		return connection;
 	}
 
@@ -193,7 +218,7 @@ class ModuleGraph {
 	 * @returns {Module} the referenced module
 	 */
 	getModule(dependency) {
-		const connection = this._dependencyMap.get(dependency);
+		const { connection } = this._getModuleGraphDependency(dependency);
 		return connection !== undefined ? connection.module : null;
 	}
 
@@ -202,7 +227,7 @@ class ModuleGraph {
 	 * @returns {Module} the referencing module
 	 */
 	getOrigin(dependency) {
-		const connection = this._dependencyMap.get(dependency);
+		const { connection } = this._getModuleGraphDependency(dependency);
 		return connection !== undefined ? connection.originModule : null;
 	}
 
@@ -211,7 +236,7 @@ class ModuleGraph {
 	 * @returns {Module} the original referencing module
 	 */
 	getResolvedOrigin(dependency) {
-		const connection = this._dependencyMap.get(dependency);
+		const { connection } = this._getModuleGraphDependency(dependency);
 		return connection !== undefined ? connection.resolvedOriginModule : null;
 	}