chore: refactor

Author: ota-meshi

src/parser/typescript/analyze/index.ts

@@ -12,21 +12,22 @@ import {
 } from "../../../scope";
 import { addElementsToSortedArray, sortedLastIndex } from "../../../utils";
 import { parseScriptWithoutAnalyzeScope } from "../../script";
-import { TypeScriptContext } from "../context";
+import { VirtualTypeScriptContext } from "../context";
 import type { TSESParseForESLintResult } from "../types";
 import type ESTree from "estree";
 
 const RESERVED_NAMES = new Set<string>(["$$props", "$$restProps", "$$slots"]);
 /**
  * Analyze <script> block script
  * Modify the source code to provide correct type information for svelte special variables and scopes.
+ * See https://github.com/ota-meshi/svelte-eslint-parser/blob/main/docs/internal-mechanism.md#scope-types
  */
 export function analyzeScript(
   code: { script: string; render: string },
   attrs: Record<string, string | undefined>,
   parserOptions: any
-): TypeScriptContext {
-  const ctx = new TypeScriptContext(code.script + code.render);
+): VirtualTypeScriptContext {
+  const ctx = new VirtualTypeScriptContext(code.script + code.render);
   ctx.appendOriginal(/^\s*/u.exec(code.script)![0].length);
 
   // We will need to parse TypeScript once to extract the reactive variables.
@@ -54,14 +55,13 @@ export function analyzeScript(
   ctx.appendScript(`function ${renderFunctionName}(){`);
   ctx.appendOriginalToEnd();
   ctx.appendScript(`}`);
-  ctx.restoreContext.addRestoreStatementProcess((node, context) => {
+  ctx.restoreContext.addRestoreStatementProcess((node, result) => {
     if (
       node.type !== "FunctionDeclaration" ||
       node.id.name !== renderFunctionName
     ) {
       return false;
     }
-    const result = context.result;
     const program = result.ast;
     program.body.splice(program.body.indexOf(node), 1, ...node.body.body);
     for (const body of node.body.body) {
@@ -81,7 +81,7 @@ export function analyzeScript(
  */
 function analyzeStoreReferenceNamesAndExtractThroughIdentifiers(
   result: TSESParseForESLintResult,
-  ctx: TypeScriptContext
+  ctx: VirtualTypeScriptContext
 ) {
   const scopeManager = result.scopeManager;
   const programScope = getProgramScope(scopeManager as ScopeManager);
@@ -110,14 +110,13 @@ function analyzeStoreReferenceNamesAndExtractThroughIdentifiers(
 : never
 : T;`
     );
-    ctx.restoreContext.addRestoreStatementProcess((node, context) => {
+    ctx.restoreContext.addRestoreStatementProcess((node, result) => {
       if (
         node.type !== "TSTypeAliasDeclaration" ||
         node.id.name !== storeValueTypeName
       ) {
         return false;
       }
-      const result = context.result;
       const program = result.ast;
       program.body.splice(program.body.indexOf(node), 1);
 
@@ -135,7 +134,7 @@ function analyzeStoreReferenceNamesAndExtractThroughIdentifiers(
       ctx.appendScript(
         `declare let ${nm}: ${storeValueTypeName}<typeof ${realName}>;`
       );
-      ctx.restoreContext.addRestoreStatementProcess((node, context) => {
+      ctx.restoreContext.addRestoreStatementProcess((node, result) => {
         if (
           node.type !== "VariableDeclaration" ||
           !node.declare ||
@@ -145,7 +144,6 @@ function analyzeStoreReferenceNamesAndExtractThroughIdentifiers(
         ) {
           return false;
         }
-        const result = context.result;
         const program = result.ast;
         program.body.splice(program.body.indexOf(node), 1);
 
@@ -171,7 +169,7 @@ function analyzeStoreReferenceNamesAndExtractThroughIdentifiers(
 function analyzeReactiveScopes(
   result: TSESParseForESLintResult,
   throughIds: (TSESTree.Identifier | TSESTree.JSXIdentifier)[],
-  ctx: TypeScriptContext
+  ctx: VirtualTypeScriptContext
 ) {
   for (const statement of result.ast.body) {
     if (statement.type === "LabeledStatement" && statement.label.name === "$") {
@@ -214,7 +212,7 @@ function transformForDeclareReactiveVar(
   id: TSESTree.Identifier | TSESTree.ArrayPattern | TSESTree.ObjectPattern,
   expression: TSESTree.AssignmentExpression,
   tokens: TSESTree.Token[],
-  ctx: TypeScriptContext
+  ctx: VirtualTypeScriptContext
 ): void {
   // e.g.
   //  From:
@@ -281,7 +279,7 @@ function transformForDeclareReactiveVar(
   ctx.appendScript(`}`);
 
   // eslint-disable-next-line complexity -- ignore X(
-  ctx.restoreContext.addRestoreStatementProcess((node, context) => {
+  ctx.restoreContext.addRestoreStatementProcess((node, result) => {
     if ((node as any).type !== "SvelteReactiveStatement") {
       return false;
     }
@@ -303,7 +301,6 @@ function transformForDeclareReactiveVar(
     ) {
       return false;
     }
-    const result = context.result;
     const program = result.ast;
     const nextIndex = program.body.indexOf(node) + 1;
     const fnDecl = program.body[nextIndex];
@@ -375,7 +372,7 @@ function transformForDeclareReactiveVar(
  */
 function transformForReactiveStatement(
   statement: TSESTree.LabeledStatement,
-  ctx: TypeScriptContext
+  ctx: VirtualTypeScriptContext
 ) {
   const functionId = ctx.generateUniqueId("reactiveStatementScopeFunction");
   const originalBody = statement.body;
@@ -390,7 +387,7 @@ function transformForReactiveStatement(
   }
   ctx.appendOriginal(statement.range[1]);
 
-  ctx.restoreContext.addRestoreStatementProcess((node, context) => {
+  ctx.restoreContext.addRestoreStatementProcess((node, result) => {
     if ((node as any).type !== "SvelteReactiveStatement") {
       return false;
     }
@@ -406,7 +403,6 @@ function transformForReactiveStatement(
     }
     reactiveStatement.body.parent = reactiveStatement;
 
-    const result = context.result;
     const scopeManager = result.scopeManager as ScopeManager;
     removeFunctionScope(body, scopeManager);
     return true;

src/parser/typescript/context.ts

@@ -2,7 +2,11 @@ import { UniqueIdGenerator } from "../../context/unique";
 import { RestoreContext } from "./restore";
 import type { TSESParseForESLintResult } from "./types";
 
-export class TypeScriptContext {
+/**
+ * Context for virtual TypeScript code.
+ * See https://github.com/ota-meshi/svelte-eslint-parser/blob/main/docs/internal-mechanism.md#scope-types
+ */
+export class VirtualTypeScriptContext {
   private readonly originalCode: string;
 
   public readonly restoreContext: RestoreContext;

src/parser/typescript/restore.ts

@@ -6,7 +6,7 @@ import type { TSESParseForESLintResult } from "./types";
 /**
  * A function that restores the statement.
  * @param node The node to restore.
- * @param context The context to restore.
+ * @param result The result of parsing.
  * @returns
  *   If `false`, it indicates that the specified node was not processed.
  *
@@ -15,7 +15,7 @@ import type { TSESParseForESLintResult } from "./types";
  */
 type RestoreStatementProcess = (
   node: TSESTree.Statement,
-  context: RestoreNodeProcessContext
+  result: TSESParseForESLintResult
 ) => boolean;
 
 export class RestoreContext {
@@ -52,15 +52,15 @@ export class RestoreContext {
    * Restore AST nodes
    */
   public restore(result: TSESParseForESLintResult): void {
-    const parentMap = remapLocationsAndGetParentMap(result, {
+    remapLocations(result, {
       remapLocation: (n) => this.remapLocation(n),
       removeToken: (token) =>
         this.fragments.some(
           (f) => f.start <= token.range[0] && token.range[1] <= f.end
         ),
     });
 
-    restoreStatements(result, this.restoreStatementProcesses, parentMap);
+    restoreStatements(result, this.restoreStatementProcesses);
 
     // Adjust program node location
     const firstOffset = Math.min(
@@ -137,26 +137,8 @@ export class RestoreContext {
   }
 }
 
-export class RestoreNodeProcessContext {
-  public readonly result: TSESParseForESLintResult;
-
-  private readonly parentMap: Map<TSESTree.Node, TSESTree.Node | null>;
-
-  public constructor(
-    result: TSESParseForESLintResult,
-    parentMap: Map<TSESTree.Node, TSESTree.Node | null>
-  ) {
-    this.result = result;
-    this.parentMap = parentMap;
-  }
-
-  public getParent(node: TSESTree.Node): TSESTree.Node | null {
-    return this.parentMap.get(node) || null;
-  }
-}
-
-/** Restore locations and generate parent map */
-function remapLocationsAndGetParentMap(
+/** Restore locations */
+function remapLocations(
   result: TSESParseForESLintResult,
   {
     remapLocation,
@@ -166,13 +148,13 @@ function remapLocationsAndGetParentMap(
     removeToken: (node: TSESTree.Token) => boolean;
   }
 ) {
-  const parentMap = new Map<TSESTree.Node, TSESTree.Node | null>();
+  const traversed = new Map<TSESTree.Node, TSESTree.Node | null>();
   // remap locations
   traverseNodes(result.ast, {
     visitorKeys: result.visitorKeys,
     enterNode: (node, p) => {
-      if (!parentMap.has(node)) {
-        parentMap.set(node, p);
+      if (!traversed.has(node)) {
+        traversed.set(node, p);
 
         remapLocation(node);
       }
@@ -193,24 +175,20 @@ function remapLocationsAndGetParentMap(
   for (const token of result.ast.comments || []) {
     remapLocation(token);
   }
-
-  return parentMap;
 }
 
 /** Restore statement nodes */
 function restoreStatements(
   result: TSESParseForESLintResult,
-  restoreStatementProcesses: RestoreStatementProcess[],
-  parentMap: Map<TSESTree.Node, TSESTree.Node | null>
+  restoreStatementProcesses: RestoreStatementProcess[]
 ) {
-  const context = new RestoreNodeProcessContext(result, parentMap);
   const restoreStatementProcessesSet = new Set(restoreStatementProcesses);
   for (const node of [...result.ast.body]) {
     if (!restoreStatementProcessesSet.size) {
       break;
     }
     for (const proc of restoreStatementProcessesSet) {
-      if (proc(node, context)) {
+      if (proc(node, result)) {
         restoreStatementProcessesSet.delete(proc);
         break;
       }