add resolveByProperty to cleverMerge

lib/ResolverFactory.js

@@ -8,9 +8,9 @@
 const Factory = require("enhanced-resolve").ResolverFactory;
 const { HookMap, SyncHook, SyncWaterfallHook } = require("tapable");
 const {
-	cleverMerge,
 	cachedCleverMerge,
-	removeOperations
+	removeOperations,
+	resolveByProperty
 } = require("./util/cleverMerge");
 
 /** @typedef {import("enhanced-resolve").ResolveOptions} ResolveOptions */
@@ -34,12 +34,7 @@ const EMPTY_RESOLVE_OPTIONS = {};
  * @returns {ResolveOptions} merged options
  */
 const convertToResolveOptions = resolveOptionsWithDepType => {
-	const {
-		dependencyType,
-		byDependency,
-		plugins,
-		...remaining
-	} = resolveOptionsWithDepType;
+	const { dependencyType, plugins, ...remaining } = resolveOptionsWithDepType;
 
 	// check type compat
 	/** @type {Partial<ResolveOptions>} */
@@ -60,16 +55,9 @@ const convertToResolveOptions = resolveOptionsWithDepType => {
 	// These weird types validate that we checked all non-optional properties
 	const options = /** @type {Partial<ResolveOptions> & Pick<ResolveOptions, "fileSystem">} */ (partialOptions);
 
-	if (!resolveOptionsWithDepType.byDependency) {
-		return options;
-	}
-
-	const usedDependencyType =
-		dependencyType in byDependency ? `${dependencyType}` : "default";
-
-	const depDependentOptions = byDependency[usedDependencyType];
-	if (!depDependentOptions) return options;
-	return removeOperations(cleverMerge(options, depDependentOptions));
+	return removeOperations(
+		resolveByProperty(options, "byDependency", dependencyType)
+	);
 };
 
 /**

lib/util/cleverMerge.js

@@ -448,8 +448,39 @@ const removeOperations = obj => {
 	return newObj;
 };
 
+/**
+ * @param {object} obj the object
+ * @param {string} byProperty the by description
+ * @param  {...any} values values
+ * @returns {object} object with merged byProperty
+ */
+const resolveByProperty = (obj, byProperty, ...values) => {
+	if (!(byProperty in obj)) {
+		return obj;
+	}
+	const { [byProperty]: byValue, ...remaining } = obj;
+	if (typeof byValue === "object") {
+		const key = values[0];
+		if (key in byValue) {
+			return cleverMerge(remaining, byValue[key]);
+		} else if ("default" in byValue) {
+			return cleverMerge(remaining, byValue.default);
+		} else {
+			return remaining;
+		}
+	} else if (typeof byValue === "function") {
+		const result = resolveByProperty(
+			byValue.apply(null, values),
+			byProperty,
+			...values
+		);
+		return cleverMerge(remaining, result);
+	}
+};
+
 exports.cachedSetProperty = cachedSetProperty;
 exports.cachedCleverMerge = cachedCleverMerge;
 exports.cleverMerge = cleverMerge;
+exports.resolveByProperty = resolveByProperty;
 exports.removeOperations = removeOperations;
 exports.DELETE = DELETE;