refactor: Use @eslint/plugin-kit (#22)

package.json

@@ -61,6 +61,7 @@
   ],
   "license": "Apache-2.0",
   "dependencies": {
+    "@eslint/plugin-kit": "^0.1.0",
     "@humanwhocodes/momoa": "^3.2.0"
   },
   "devDependencies": {

src/languages/json-source-code.js

@@ -8,6 +8,7 @@
 //-----------------------------------------------------------------------------
 
 import { iterator } from "@humanwhocodes/momoa";
+import { VisitNodeStep, TextSourceCodeBase } from "@eslint/plugin-kit";
 
 //-----------------------------------------------------------------------------
 // Types
@@ -29,41 +30,13 @@ import { iterator } from "@humanwhocodes/momoa";
 
 /**
  * A class to represent a step in the traversal process.
- * @implements {VisitTraversalStep}
  */
-class JSONTraversalStep {
-	/**
-	 * The type of the step.
-	 * @type {"visit"}
-	 * @readonly
-	 */
-	type = "visit";
-
-	/**
-	 * The kind of the step. Represents the same data as the `type` property
-	 * but it's a number for performance.
-	 * @type {1}
-	 * @readonly
-	 */
-	kind = 1;
-
+class JSONTraversalStep extends VisitNodeStep {
 	/**
 	 * The target of the step.
 	 * @type {JSONNode}
 	 */
-	target;
-
-	/**
-	 * The phase of the step.
-	 * @type {1|2}
-	 */
-	phase;
-
-	/**
-	 * The arguments of the step.
-	 * @type {Array<any>}
-	 */
-	args;
+	target = undefined;
 
 	/**
 	 * Creates a new instance.
@@ -73,9 +46,9 @@ class JSONTraversalStep {
 	 * @param {Array<any>} options.args The arguments of the step.
 	 */
 	constructor({ target, phase, args }) {
+		super({ target, phase, args });
+
 		this.target = target;
-		this.phase = phase;
-		this.args = args;
 	}
 }
 
@@ -85,9 +58,8 @@ class JSONTraversalStep {
 
 /**
  * JSON Source Code Object
- * @implements {TextSourceCode}
  */
-export class JSONSourceCode {
+export class JSONSourceCode extends TextSourceCodeBase {
 	/**
 	 * Cached traversal steps.
 	 * @type {Array<JSONTraversalStep>|undefined}
@@ -100,23 +72,11 @@ export class JSONSourceCode {
 	 */
 	#parents = new WeakMap();
 
-	/**
-	 * The lines of text in the source code.
-	 * @type {Array<string>}
-	 */
-	#lines;
-
 	/**
 	 * The AST of the source code.
 	 * @type {DocumentNode}
 	 */
-	ast;
-
-	/**
-	 * The text of the source code.
-	 * @type {string}
-	 */
-	text;
+	ast = undefined;
 
 	/**
 	 * The comment node in the source code.
@@ -131,35 +91,13 @@ export class JSONSourceCode {
 	 * @param {DocumentNode} options.ast The root AST node.
 	 */
 	constructor({ text, ast }) {
+		super({ text, ast });
 		this.ast = ast;
-		this.text = text;
-		this.comments = ast.tokens.filter(token =>
-			token.type.endsWith("Comment"),
-		);
-	}
-
-	/* eslint-disable class-methods-use-this -- Required to complete interface. */
-
-	/**
-	 * Returns the loc information for the given node or token.
-	 * @param {JSONNode|JSONToken} nodeOrToken The node or token to get the loc information for.
-	 * @returns {SourceLocation} The loc information for the node or token.
-	 */
-	getLoc(nodeOrToken) {
-		return nodeOrToken.loc;
-	}
-
-	/**
-	 * Returns the range information for the given node or token.
-	 * @param {JSONNode|JSONToken} nodeOrToken The node or token to get the range information for.
-	 * @returns {SourceRange} The range information for the node or token.
-	 */
-	getRange(nodeOrToken) {
-		return nodeOrToken.range;
+		this.comments = ast.tokens
+			? ast.tokens.filter(token => token.type.endsWith("Comment"))
+			: [];
 	}
 
-	/* eslint-enable class-methods-use-this -- Required to complete interface. */
-
 	/**
 	 * Returns the parent of the given node.
 	 * @param {JSONNode} node The node to get the parent of.
@@ -169,61 +107,6 @@ export class JSONSourceCode {
 		return this.#parents.get(node);
 	}
 
-	/**
-	 * Gets all the ancestors of a given node
-	 * @param {JSONNode} node The node
-	 * @returns {Array<JSONNode>} All the ancestor nodes in the AST, not including the provided node, starting
-	 * from the root node at index 0 and going inwards to the parent node.
-	 * @throws {TypeError} When `node` is missing.
-	 */
-	getAncestors(node) {
-		if (!node) {
-			throw new TypeError("Missing required argument: node.");
-		}
-
-		const ancestorsStartingAtParent = [];
-
-		for (
-			let ancestor = this.#parents.get(node);
-			ancestor;
-			ancestor = this.#parents.get(ancestor)
-		) {
-			ancestorsStartingAtParent.push(ancestor);
-		}
-
-		return ancestorsStartingAtParent.reverse();
-	}
-
-	/**
-	 * Gets the source code for the given node.
-	 * @param {JSONNode} [node] The AST node to get the text for.
-	 * @param {number} [beforeCount] The number of characters before the node to retrieve.
-	 * @param {number} [afterCount] The number of characters after the node to retrieve.
-	 * @returns {string} The text representing the AST node.
-	 * @public
-	 */
-	getText(node, beforeCount, afterCount) {
-		if (node) {
-			return this.text.slice(
-				Math.max(node.range[0] - (beforeCount || 0), 0),
-				node.range[1] + (afterCount || 0),
-			);
-		}
-		return this.text;
-	}
-
-	/**
-	 * Gets the entire source text split into an array of lines.
-	 * @returns {Array} The source text as an array of lines.
-	 * @public
-	 */
-	get lines() {
-		if (!this.#lines) {
-			this.#lines = this.text.split(/\r?\n/gu);
-		}
-		return this.#lines;
-	}
-
 	/**
 	 * Traverse the source code and return the steps that were taken.
 	 * @returns {Iterable<JSONTraversalStep>} The steps that were taken while traversing the source code.
@@ -238,7 +121,10 @@ export class JSONSourceCode {
 		const steps = (this.#steps = []);
 
 		for (const { node, parent, phase } of iterator(this.ast)) {
-			this.#parents.set(node, parent);
+			if (parent) {
+				this.#parents.set(node, parent);
+			}
+
 			steps.push(
 				new JSONTraversalStep({
 					target: node,

tests/languages/json-source-code.test.js

@@ -142,7 +142,7 @@ describe("JSONSourceCode", () => {
 		});
 	});
 
-	describe("get lines", () => {
+	describe("lines", () => {
 		it("should return an array of lines", () => {
 			const file = { body: "{\n//test\n}", path: "test.jsonc" };
 			const language = new JSONLanguage({ mode: "jsonc" });
@@ -155,4 +155,124 @@ describe("JSONSourceCode", () => {
 			assert.deepStrictEqual(sourceCode.lines, ["{", "//test", "}"]);
 		});
 	});
+
+	describe("getParent()", () => {
+		it("should return the parent node for a given node", () => {
+			const ast = {
+				type: "Document",
+				body: {
+					type: "Object",
+					properties: [],
+				},
+				tokens: [],
+			};
+			const text = "{}";
+			const sourceCode = new JSONSourceCode({
+				text,
+				ast,
+			});
+			const node = ast.body;
+
+			// call traverse to initialize the parent map
+			sourceCode.traverse();
+
+			assert.strictEqual(sourceCode.getParent(node), ast);
+		});
+
+		it("should return the parent node for a deeply nested node", () => {
+			const ast = {
+				type: "Document",
+				body: {
+					type: "Object",
+					members: [
+						{
+							type: "Member",
+							name: {
+								type: "Identifier",
+								name: "foo",
+							},
+							value: {
+								type: "Object",
+								properties: [],
+							},
+						},
+					],
+				},
+				tokens: [],
+			};
+			const text = '{"foo":{}}';
+			const sourceCode = new JSONSourceCode({
+				text,
+				ast,
+			});
+			const node = ast.body.members[0].value;
+
+			// call traverse to initialize the parent map
+			sourceCode.traverse();
+
+			assert.strictEqual(sourceCode.getParent(node), ast.body.members[0]);
+		});
+	});
+
+	describe("getAncestors()", () => {
+		it("should return an array of ancestors for a given node", () => {
+			const ast = {
+				type: "Document",
+				body: {
+					type: "Object",
+					members: [],
+				},
+				tokens: [],
+			};
+			const text = "{}";
+			const sourceCode = new JSONSourceCode({
+				text,
+				ast,
+			});
+			const node = ast.body;
+
+			// call traverse to initialize the parent map
+			sourceCode.traverse();
+
+			assert.deepStrictEqual(sourceCode.getAncestors(node), [ast]);
+		});
+
+		it("should return an array of ancestors for a deeply nested node", () => {
+			const ast = {
+				type: "Document",
+				body: {
+					type: "Object",
+					members: [
+						{
+							type: "Member",
+							name: {
+								type: "Identifier",
+								name: "foo",
+							},
+							value: {
+								type: "Object",
+								members: [],
+							},
+						},
+					],
+				},
+				tokens: [],
+			};
+			const text = '{"foo":{}}';
+			const sourceCode = new JSONSourceCode({
+				text,
+				ast,
+			});
+			const node = ast.body.members[0].value;
+
+			// call traverse to initialize the parent map
+			sourceCode.traverse();
+
+			assert.deepStrictEqual(sourceCode.getAncestors(node), [
+				ast,
+				ast.body,
+				ast.body.members[0],
+			]);
+		});
+	});
 });