feat(experimental-utils): extract isTokenOfTypeWithConditions out o…

…f `ast-utils`' `predicates`
typescript-eslint · Oct 8, 2021 · ad55cbb · ad55cbb
1 parent 3650589
commit ad55cbb
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Showing 2 changed files with 38 additions and 18 deletions.
diff --git a/packages/experimental-utils/src/ast-utils/helpers.ts b/packages/experimental-utils/src/ast-utils/helpers.ts
@@ -1,4 +1,7 @@
-import { AST_NODE_TYPES, TSESTree } from '../ts-estree';
+import { AST_NODE_TYPES, AST_TOKEN_TYPES, TSESTree } from '../ts-estree';
+
+type ObjectEntry<BaseType> = [keyof BaseType, BaseType[keyof BaseType]];
+type ObjectEntries<BaseType> = Array<ObjectEntry<BaseType>>;
 
 export const isNodeOfType =
   <NodeType extends AST_NODE_TYPES>(nodeType: NodeType) =>
@@ -14,8 +17,6 @@ export const isNodeOfTypes =
   ): node is TSESTree.Node & { type: NodeTypes[number] } =>
     !!node && nodeTypes.includes(node.type);
 
-type ObjectEntry<BaseType> = [keyof BaseType, BaseType[keyof BaseType]];
-type ObjectEntries<BaseType> = Array<ObjectEntry<BaseType>>;
 export const isNodeOfTypeWithConditions = <
   NodeType extends AST_NODE_TYPES,
   Conditions extends Partial<TSESTree.Node & { type: NodeType }>,
@@ -35,3 +36,23 @@ export const isNodeOfTypeWithConditions = <
     node?.type === nodeType &&
     entries.every(([key, value]) => node[key] === value);
 };
+
+export const isTokenOfTypeWithConditions = <
+  TokenType extends AST_TOKEN_TYPES,
+  Conditions extends Partial<TSESTree.Token & { type: TokenType }>,
+>(
+  tokenType: TokenType,
+  conditions: Conditions,
+): ((
+  token: TSESTree.Token | null | undefined,
+) => token is TSESTree.Token & { type: TokenType } & Conditions) => {
+  const entries = Object.entries(conditions) as ObjectEntries<
+    TSESTree.Token & { type: TokenType }
+  >;
+
+  return (
+    token: TSESTree.Token | null | undefined,
+  ): token is TSESTree.Token & { type: TokenType } & Conditions =>
+    token?.type === tokenType &&
+    entries.every(([key, value]) => token[key] === value);
+};
diff --git a/packages/experimental-utils/src/ast-utils/predicates.ts b/packages/experimental-utils/src/ast-utils/predicates.ts
@@ -4,13 +4,14 @@ import {
   isNodeOfType,
   isNodeOfTypes,
   isNodeOfTypeWithConditions,
+  isTokenOfTypeWithConditions,
 } from './helpers';
 
-function isOptionalChainPunctuator(
-  token: TSESTree.Token,
-): token is TSESTree.PunctuatorToken & { value: '?.' } {
-  return token.type === AST_TOKEN_TYPES.Punctuator && token.value === '?.';
-}
+const isOptionalChainPunctuator = isTokenOfTypeWithConditions(
+  AST_TOKEN_TYPES.Punctuator,
+  { value: '?.' },
+);
+
 function isNotOptionalChainPunctuator(
   token: TSESTree.Token,
 ): token is Exclude<
@@ -20,11 +21,11 @@ function isNotOptionalChainPunctuator(
   return !isOptionalChainPunctuator(token);
 }
 
-function isNonNullAssertionPunctuator(
-  token: TSESTree.Token,
-): token is TSESTree.PunctuatorToken & { value: '!' } {
-  return token.type === AST_TOKEN_TYPES.Punctuator && token.value === '!';
-}
+const isNonNullAssertionPunctuator = isTokenOfTypeWithConditions(
+  AST_TOKEN_TYPES.Punctuator,
+  { value: '!' },
+);
+
 function isNotNonNullAssertionPunctuator(
   token: TSESTree.Token,
 ): token is Exclude<TSESTree.Token, TSESTree.PunctuatorToken & { value: '!' }> {
@@ -138,11 +139,9 @@ const isAwaitExpression = isNodeOfType(AST_NODE_TYPES.AwaitExpression);
 /**
  * Checks if a possible token is the `await` keyword.
  */
-function isAwaitKeyword(
-  node: TSESTree.Token | undefined | null,
-): node is TSESTree.IdentifierToken & { value: 'await' } {
-  return node?.type === AST_TOKEN_TYPES.Identifier && node.value === 'await';
-}
+const isAwaitKeyword = isTokenOfTypeWithConditions(AST_TOKEN_TYPES.Identifier, {
+  value: 'await',
+});
 
 const isLoop = isNodeOfTypes([
   AST_NODE_TYPES.DoWhileStatement,