chore(utils): merge AccessorNode guards

Author: G-Rath

src/rules/prefer-to-have-length.ts

@@ -1,9 +1,9 @@
 import { AST_NODE_TYPES } from '@typescript-eslint/experimental-utils';
 import {
   createRule,
-  isAccessorNode,
   isExpectCall,
   isParsedEqualityMatcherCall,
+  isSupportedAccessor,
   parseExpectCall,
 } from './utils';
 
@@ -42,7 +42,7 @@ export default createRule({
           !isParsedEqualityMatcherCall(matcher) ||
           !argument ||
           argument.type !== AST_NODE_TYPES.MemberExpression ||
-          !isAccessorNode(argument.property, 'length') ||
+          !isSupportedAccessor(argument.property, 'length') ||
           argument.property.type !== AST_NODE_TYPES.Identifier
         ) {
           return;

src/rules/utils.ts

@@ -162,35 +162,51 @@ const isIdentifier = <V extends string>(
   node.type === AST_NODE_TYPES.Identifier &&
   (name === undefined || node.name === name);
 
+/**
+ * Checks if the given `node` is a "supported accessor".
+ *
+ * This means that it's a node can be used to access properties,
+ * and who's "value" can be statically determined.
+ *
+ * `MemberExpression` nodes most commonly contain accessors,
+ * but it's possible for other nodes to contain them.
+ *
+ * If a `value` is provided & the `node` is an `AccessorNode`,
+ * the `value` will be compared to that of the `AccessorNode`.
+ *
+ * Note that `value` here refers to the normalised value.
+ * The property that holds the value is not always called `name`.
+ *
+ * @param {Node} node
+ * @param {V?} value
+ *
+ * @return {node is AccessorNode<V>}
+ *
+ * @template V
+ */
 export const isSupportedAccessor = <V extends string>(
   node: TSESTree.Node,
   value?: V,
 ): node is AccessorNode<V> =>
   isIdentifier(node, value) || isStringNode(node, value);
 
+/**
+ * Gets the value of the given `AccessorNode`,
+ * account for the different node types.
+ *
+ * @param {AccessorNode<S>} accessor
+ *
+ * @return {S}
+ *
+ * @template S
+ */
 export const getAccessorValue = <S extends string = string>(
   accessor: AccessorNode<S>,
 ): S =>
   accessor.type === AST_NODE_TYPES.Identifier
     ? accessor.name
     : getStringValue(accessor);
 
-/**
- * Checks if the given `node` is an `AccessorExpression` with the specific `value`.
- *
- * @param {Node} node
- * @param {V} accessor
- *
- * @return {node is SpecificAccessorExpression<V>}
- *
- * @template V
- */
-export const isAccessorNode = <V extends string>(
-  node: TSESTree.Node,
-  accessor: V,
-): node is AccessorNode<V> =>
-  isIdentifier(node, accessor) || isStringNode(node, accessor);
-
 export interface ValidExpectCall<
   Argument extends TSESTree.Expression = TSESTree.Expression
 > extends ExpectCall {
@@ -215,7 +231,7 @@ type AccessorNode<Specifics extends string = string> =
 type ExpectAccessor = AccessorNode<'expect'>;
 
 export const isExpectAccessor = (node: TSESTree.Node): node is ExpectAccessor =>
-  isAccessorNode(node, 'expect');
+  isSupportedAccessor(node, 'expect');
 
 export interface ExpectCall extends TSESTree.CallExpression {
   callee: AccessorNode<'expect'>;