feat(linter/plugins): implement SourceCode#getAncestors (#14346)

Implement `sourceCode.getAncestors` method to get all the ancestors of an AST node.

Author: overlookmotel

apps/oxlint/src-js/plugins/source_code.ts

@@ -518,16 +518,7 @@ export const SOURCE_CODE = Object.freeze({
     throw new Error('`sourceCode.commentsExistBetween` not implemented yet'); // TODO
   },
 
-  /**
-   * Get all the ancestors of a given node.
-   * @param node - AST node
-   * @returns 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.
-   */
-  // oxlint-disable-next-line no-unused-vars
-  getAncestors(node: Node): Node[] {
-    throw new Error('`sourceCode.getAncestors` not implemented yet'); // TODO
-  },
+  getAncestors,
 
   /**
    * Get the variables that `node` defines.
@@ -655,6 +646,26 @@ export function getIndexFromLoc(loc: LineColumn): number {
   throw new TypeError('Expected `loc` to be an object with integer `line` and `column` properties.');
 }
 
+/**
+ * Get all the ancestors of a given node.
+ * @param node - AST node
+ * @returns 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.
+ */
+function getAncestors(node: Node): Node[] {
+  const ancestors = [];
+
+  for (
+    let ancestor = (node as unknown as { parent: Node }).parent;
+    ancestor;
+    ancestor = (ancestor as unknown as { parent: Node }).parent
+  ) {
+    ancestors.push(ancestor);
+  }
+
+  return ancestors.reverse();
+}
+
 // Options for various `SourceCode` methods e.g. `getFirstToken`.
 export interface SkipOptions {
   // Number of skipping tokens

apps/oxlint/test/fixtures/parent/output.snap.md

@@ -3,73 +3,97 @@
 
 # stdout
 ```
-  x parents(check): VariableDeclaration -> Program
+  x parents(check): VariableDeclaration:
+  | parent: Program
+  | ancestors: [ Program ]
    ,-[files/index.js:1:1]
  1 | const obj = { a: [b, c], ...d };
    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    `----
 
-  x parents(check): Program -> null
+  x parents(check): Program:
+  | parent: undefined
+  | ancestors: [  ]
    ,-[files/index.js:1:1]
  1 | const obj = { a: [b, c], ...d };
    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    `----
 
-  x parents(check): Identifier -> VariableDeclarator
+  x parents(check): Identifier:
+  | parent: VariableDeclarator
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator ]
    ,-[files/index.js:1:7]
  1 | const obj = { a: [b, c], ...d };
    :       ^^^
    `----
 
-  x parents(check): VariableDeclarator -> VariableDeclaration
+  x parents(check): VariableDeclarator:
+  | parent: VariableDeclaration
+  | ancestors: [ Program, VariableDeclaration ]
    ,-[files/index.js:1:7]
  1 | const obj = { a: [b, c], ...d };
    :       ^^^^^^^^^^^^^^^^^^^^^^^^^
    `----
 
-  x parents(check): ObjectExpression -> VariableDeclarator
+  x parents(check): ObjectExpression:
+  | parent: VariableDeclarator
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator ]
    ,-[files/index.js:1:13]
  1 | const obj = { a: [b, c], ...d };
    :             ^^^^^^^^^^^^^^^^^^^
    `----
 
-  x parents(check): Identifier -> Property
+  x parents(check): Identifier:
+  | parent: Property
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator, ObjectExpression, Property ]
    ,-[files/index.js:1:15]
  1 | const obj = { a: [b, c], ...d };
    :               ^
    `----
 
-  x parents(check): Property -> ObjectExpression
+  x parents(check): Property:
+  | parent: ObjectExpression
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator, ObjectExpression ]
    ,-[files/index.js:1:15]
  1 | const obj = { a: [b, c], ...d };
    :               ^^^^^^^^^
    `----
 
-  x parents(check): ArrayExpression -> Property
+  x parents(check): ArrayExpression:
+  | parent: Property
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator, ObjectExpression, Property ]
    ,-[files/index.js:1:18]
  1 | const obj = { a: [b, c], ...d };
    :                  ^^^^^^
    `----
 
-  x parents(check): Identifier -> ArrayExpression
+  x parents(check): Identifier:
+  | parent: ArrayExpression
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator, ObjectExpression, Property, ArrayExpression ]
    ,-[files/index.js:1:19]
  1 | const obj = { a: [b, c], ...d };
    :                   ^
    `----
 
-  x parents(check): Identifier -> ArrayExpression
+  x parents(check): Identifier:
+  | parent: ArrayExpression
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator, ObjectExpression, Property, ArrayExpression ]
    ,-[files/index.js:1:22]
  1 | const obj = { a: [b, c], ...d };
    :                      ^
    `----
 
-  x parents(check): SpreadElement -> ObjectExpression
+  x parents(check): SpreadElement:
+  | parent: ObjectExpression
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator, ObjectExpression ]
    ,-[files/index.js:1:26]
  1 | const obj = { a: [b, c], ...d };
    :                          ^^^^
    `----
 
-  x parents(check): Identifier -> SpreadElement
+  x parents(check): Identifier:
+  | parent: SpreadElement
+  | ancestors: [ Program, VariableDeclaration, VariableDeclarator, ObjectExpression, SpreadElement ]
    ,-[files/index.js:1:29]
  1 | const obj = { a: [b, c], ...d };
    :                             ^

apps/oxlint/test/fixtures/parent/plugin.ts

@@ -7,31 +7,25 @@ const plugin: Plugin = {
   rules: {
     check: {
       create(context) {
+        function reportAncestry(node: any) {
+          context.report({
+            message: `${node.type}:\n` +
+              `parent: ${node.parent?.type}\n` +
+              // @ts-ignore
+              `ancestors: [ ${context.sourceCode.getAncestors(node).map(node => node.type).join(', ')} ]`,
+            node,
+          });
+        }
+
         return {
-          Program(node) {
-            context.report({ message: `${node.type} -> ${node.parent}`, node });
-          },
-          VariableDeclaration(node) {
-            context.report({ message: `${node.type} -> ${node.parent.type}`, node });
-          },
-          VariableDeclarator(node) {
-            context.report({ message: `${node.type} -> ${node.parent.type}`, node });
-          },
-          Identifier(node) {
-            context.report({ message: `${node.type} -> ${node.parent.type}`, node });
-          },
-          ObjectExpression(node) {
-            context.report({ message: `${node.type} -> ${node.parent.type}`, node });
-          },
-          Property(node) {
-            context.report({ message: `${node.type} -> ${node.parent.type}`, node });
-          },
-          ArrayExpression(node) {
-            context.report({ message: `${node.type} -> ${node.parent.type}`, node });
-          },
-          SpreadElement(node) {
-            context.report({ message: `${node.type} -> ${node.parent.type}`, node });
-          },
+          Program: reportAncestry,
+          VariableDeclaration: reportAncestry,
+          VariableDeclarator: reportAncestry,
+          Identifier: reportAncestry,
+          ObjectExpression: reportAncestry,
+          Property: reportAncestry,
+          ArrayExpression: reportAncestry,
+          SpreadElement: reportAncestry,
         };
       },
     },