feat: add pathSegments method

Author: ashphy

src/jsonpath_js.ts

@@ -2,12 +2,18 @@ import type { JsonpathQuery } from "./grammar/ast";
 import { parse } from "./grammar/jsonpath_js";
 import { run } from "./parser";
 import type { Json } from "./types/json";
+import { escapeMemberName } from "./utils/escapeMemberName";
 
 type PathResult = {
 	value: Json;
 	path: string;
 };
 
+type PathSegmentsResult = {
+	value: Json;
+	segments: (string | number)[];
+};
+
 export class JSONPathJS {
 	rootNode: JsonpathQuery;
 
@@ -23,14 +29,39 @@ export class JSONPathJS {
 			.map((json) => json.value);
 	}
 
+	#convertPathSegmentToString(segment: string | number): string {
+		if (typeof segment === "string") {
+			if (segment === "$") {
+				return "$";
+			}
+			return `['${escapeMemberName(segment)}']`;
+		}
+		return `[${segment}]`;
+	}
+
 	paths(json: Json): PathResult[] {
+		const resultNodeList = run(json, this.rootNode);
+		return resultNodeList
+			.filter((json) => json !== undefined)
+			.map((json) => {
+				const normalizedPath = json.path
+					.map((segment) => this.#convertPathSegmentToString(segment))
+					.join("");
+				return {
+					value: json.value,
+					path: normalizedPath,
+				};
+			});
+	}
+
+	pathSegments(json: Json): PathSegmentsResult[] {
 		const resultNodeList = run(json, this.rootNode);
 		return resultNodeList
 			.filter((json) => json !== undefined)
 			.map((json) => {
 				return {
 					value: json.value,
-					path: json.path,
+					segments: json.path,
 				};
 			});
 	}

src/parser.ts

@@ -4,6 +4,6 @@ import type { Json } from "./types/json";
 import { createNode, type Node, type NodeList } from "./types/node";
 
 export function run(json: Json, query: JsonpathQuery): NodeList {
-	const rootNode: Node = createNode(json, "$");
+	const rootNode: Node = createNode(json, ["$"]);
 	return applyRoot(query, rootNode);
 }

src/types/node.ts

@@ -1,12 +1,12 @@
-import { escapeMemberName } from "../utils/escapeMemberName";
 import type { Json } from "./json";
 
 const nodeType: unique symbol = Symbol("NodeType");
 
-export type Node = { [nodeType]: unknown; value: Json; path: string };
+export type PathSegment = string | number;
+export type Node = { [nodeType]: unknown; value: Json; path: PathSegment[] };
 export type NodeList = Node[];
 
-export function createNode(json: Json, path: string): Node {
+export function createNode(json: Json, path: PathSegment[]): Node {
 	return { [nodeType]: undefined, value: json, path };
 }
 
@@ -15,14 +15,11 @@ export function addMemberPath(
 	newValue: Json,
 	memberName: string,
 ): Node {
-	return createNode(
-		newValue,
-		`${base.path}['${escapeMemberName(memberName)}']`,
-	);
+	return createNode(newValue, [...base.path, memberName]);
 }
 
 export function addIndexPath(base: Node, newValue: Json, index: number): Node {
-	return createNode(newValue, `${base.path}[${index}]`);
+	return createNode(newValue, [...base.path, index]);
 }
 
 export function isNode(node: unknown): node is Node {

tests/path_segments.test.ts

@@ -0,0 +1,53 @@
+import { expect, it } from "vitest";
+import { JSONPathJS } from "../src";
+
+const book1 = {
+	category: "reference",
+	author: "Nigel Rees",
+	title: "Sayings of the Century",
+	price: 8.95,
+};
+
+const book2 = {
+	category: "fiction",
+	author: "Evelyn Waugh",
+	title: "Sword of Honour",
+	price: 12.99,
+};
+
+const book3 = {
+	category: "fiction",
+	author: "Herman Melville",
+	title: "Moby Dick",
+	isbn: "0-553-21311-3",
+	price: 8.99,
+};
+
+const book4 = {
+	category: "fiction",
+	author: "J. R. R. Tolkien",
+	title: "The Lord of the Rings",
+	isbn: "0-395-19395-8",
+	price: 22.99,
+};
+
+const json = {
+	store: {
+		book: [book1, book2, book3, book4],
+		bicycle: {
+			color: "red",
+			price: 19.95,
+		},
+	},
+};
+
+it("test", () => {
+	const path = new JSONPathJS("$.store.book[*].author");
+	const pathSegmentsList = path.pathSegments(json).map((path) => path.segments);
+
+	expect(pathSegmentsList.length).toBe(4);
+	expect(pathSegmentsList[0]).toEqual(["$", "store", "book", 0, "author"]);
+	expect(pathSegmentsList[1]).toEqual(["$", "store", "book", 1, "author"]);
+	expect(pathSegmentsList[2]).toEqual(["$", "store", "book", 2, "author"]);
+	expect(pathSegmentsList[3]).toEqual(["$", "store", "book", 3, "author"]);
+});