From f698b6243934e358c366d79e00a4899d3398bbe2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20De=20Boey?= <info@michaeldeboey.be>
Date: Sun, 20 Jun 2021 18:13:06 +0200
Subject: [PATCH] feat(ast-spec): make `BaseNode` & `BaseToken` more type-safe

---
 packages/ast-spec/src/base/BaseNode.ts        | 21 +++++++------------
 packages/ast-spec/src/base/BaseToken.ts       |  6 ++++--
 packages/ast-spec/src/base/NodeOrTokenData.ts | 17 +++++++++++++++
 packages/ast-spec/src/index.ts                |  2 +-
 .../experimental-utils/src/ts-eslint/Rule.ts  |  4 ++--
 packages/typescript-estree/src/convert.ts     |  2 +-
 6 files changed, 32 insertions(+), 20 deletions(-)
 create mode 100644 packages/ast-spec/src/base/NodeOrTokenData.ts

diff --git a/packages/ast-spec/src/base/BaseNode.ts b/packages/ast-spec/src/base/BaseNode.ts
index 362f156832b4..797b3d351320 100644
--- a/packages/ast-spec/src/base/BaseNode.ts
+++ b/packages/ast-spec/src/base/BaseNode.ts
@@ -1,22 +1,15 @@
 // import type { Node } from '../unions/Node';
-import type { Range } from './Range';
-import type { SourceLocation } from './SourceLocation';
+import type { AST_NODE_TYPES } from '../ast-node-types';
+import type { NodeOrTokenData } from './NodeOrTokenData';
 
-export interface BaseNode {
-  /**
-   * The source location information of the node.
-   * @see {SourceLocation}
-   */
-  loc: SourceLocation;
-  /**
-   * @see {Range}
-   */
-  range: Range;
+export interface BaseNode extends NodeOrTokenData {
   /**
    * The parent node of the current node
+   *
+   * This is added in the @typescript-eslint/types package as ESLint adds it
+   * while traversing.
    */
   // parent?: Node;
 
-  // every node *will* have a type, but let the nodes define their own exact string
-  // type: string;
+  type: AST_NODE_TYPES;
 }
diff --git a/packages/ast-spec/src/base/BaseToken.ts b/packages/ast-spec/src/base/BaseToken.ts
index cdf0d1286438..8780cfcb9695 100644
--- a/packages/ast-spec/src/base/BaseToken.ts
+++ b/packages/ast-spec/src/base/BaseToken.ts
@@ -1,8 +1,10 @@
-import type { BaseNode } from './BaseNode';
+import type { AST_TOKEN_TYPES } from '../ast-token-types';
+import type { NodeOrTokenData } from './NodeOrTokenData';
 
 /*
  * Token and Comment are pseudo-nodes to represent pieces of source code
  */
-export interface BaseToken extends BaseNode {
+export interface BaseToken extends NodeOrTokenData {
+  type: AST_TOKEN_TYPES;
   value: string;
 }
diff --git a/packages/ast-spec/src/base/NodeOrTokenData.ts b/packages/ast-spec/src/base/NodeOrTokenData.ts
new file mode 100644
index 000000000000..8052278bbf02
--- /dev/null
+++ b/packages/ast-spec/src/base/NodeOrTokenData.ts
@@ -0,0 +1,17 @@
+import type { Range } from './Range';
+import type { SourceLocation } from './SourceLocation';
+
+export interface NodeOrTokenData {
+  /**
+   * The source location information of the node.
+   * @see {SourceLocation}
+   */
+  loc: SourceLocation;
+
+  /**
+   * @see {Range}
+   */
+  range: Range;
+
+  type: string;
+}
diff --git a/packages/ast-spec/src/index.ts b/packages/ast-spec/src/index.ts
index bd4b6584482d..c0dc09b70b0e 100644
--- a/packages/ast-spec/src/index.ts
+++ b/packages/ast-spec/src/index.ts
@@ -1,7 +1,7 @@
 export * from './base/Accessibility';
 export * from './base/BaseNode'; // this is exported so that the `types` package can merge the decl and add the `parent` property
-export * from './base/OptionalRangeAndLoc';
 export * from './base/LineAndColumnData';
+export * from './base/OptionalRangeAndLoc';
 export * from './base/Range';
 export * from './base/SourceLocation';
 
diff --git a/packages/experimental-utils/src/ts-eslint/Rule.ts b/packages/experimental-utils/src/ts-eslint/Rule.ts
index 20a7735f08b6..139027372236 100644
--- a/packages/experimental-utils/src/ts-eslint/Rule.ts
+++ b/packages/experimental-utils/src/ts-eslint/Rule.ts
@@ -277,7 +277,7 @@ interface RuleListener {
   ClassDeclaration?: RuleFunction<TSESTree.ClassDeclaration>;
   ClassExpression?: RuleFunction<TSESTree.ClassExpression>;
   ClassProperty?: RuleFunction<TSESTree.ClassProperty>;
-  Comment?: RuleFunction<TSESTree.Comment>;
+  // Comment?: RuleFunction<TSESTree.Comment>;
   ConditionalExpression?: RuleFunction<TSESTree.ConditionalExpression>;
   ContinueStatement?: RuleFunction<TSESTree.ContinueStatement>;
   DebuggerStatement?: RuleFunction<TSESTree.DebuggerStatement>;
@@ -338,7 +338,7 @@ interface RuleListener {
   TemplateLiteral?: RuleFunction<TSESTree.TemplateLiteral>;
   ThisExpression?: RuleFunction<TSESTree.ThisExpression>;
   ThrowStatement?: RuleFunction<TSESTree.ThrowStatement>;
-  Token?: RuleFunction<TSESTree.Token>;
+  // Token?: RuleFunction<TSESTree.Token>;
   TryStatement?: RuleFunction<TSESTree.TryStatement>;
   TSAbstractClassProperty?: RuleFunction<TSESTree.TSAbstractClassProperty>;
   TSAbstractKeyword?: RuleFunction<TSESTree.TSAbstractKeyword>;
diff --git a/packages/typescript-estree/src/convert.ts b/packages/typescript-estree/src/convert.ts
index 8ffa10ab9181..e6a8c7a934b0 100644
--- a/packages/typescript-estree/src/convert.ts
+++ b/packages/typescript-estree/src/convert.ts
@@ -199,7 +199,7 @@ export class Converter {
    */
   private registerTSNodeInNodeMap(
     node: ts.Node,
-    result: TSESTree.BaseNode | null,
+    result: TSESTree.Node | null,
   ): void {
     if (result && this.options.shouldPreserveNodeMaps) {
       if (!this.tsNodeToESTreeNodeMap.has(node)) {