Major Improvements 2

Author: graphemecluster

build/alias.ts

@@ -0,0 +1,46 @@
+const aliasArray: [string, string[]][] = [
+  [
+    "TypedNumberArray",
+    [
+      "Int8Array",
+      "Uint8Array",
+      "Uint8ClampedArray",
+      "Int16Array",
+      "Uint16Array",
+      "Int32Array",
+      "Uint32Array",
+      "Float32Array",
+      "Float64Array",
+    ],
+  ],
+  ["TypedBigIntArray", ["BigInt64Array", "BigUint64Array"]],
+];
+
+export const alias = new Map(
+  aliasArray.flatMap(([originalType, replacementTypes]) => [
+    [
+      originalType,
+      new Map(
+        replacementTypes.map((replacement) => [
+          replacement,
+          new Map([
+            [originalType, replacement],
+            [`${originalType}Constructor`, `${replacement}Constructor`],
+          ]),
+        ])
+      ),
+    ],
+    [
+      `${originalType}Constructor`,
+      new Map(
+        replacementTypes.map((replacement) => [
+          `${replacement}Constructor`,
+          new Map([
+            [originalType, replacement],
+            [`${originalType}Constructor`, `${replacement}Constructor`],
+          ]),
+        ])
+      ),
+    ],
+  ])
+);

build/logic/generate.ts

@@ -1,5 +1,6 @@
 import path from "path";
 import ts from "typescript";
+import { alias } from "../alias";
 import { upsert } from "../util/upsert";
 import { projectDir } from "./projectDir";
 
@@ -24,7 +25,7 @@ export function generate(
 
   let result = "";
 
-  const replacementTargets = scanBetterFile(libFile);
+  const replacementTargets = scanBetterFile(printer, libFile);
 
   if (replacementTargets.size === 0) {
     for (const statement of originalFile.statements) {
@@ -188,7 +189,10 @@ type ReplacementTarget = (
 /**
  * Scan better lib file to determine which statements need to be replaced.
  */
-function scanBetterFile(libFile: string): Map<string, ReplacementTarget[]> {
+function scanBetterFile(
+  printer: ts.Printer,
+  libFile: string
+): Map<string, ReplacementTarget[]> {
   const replacementTargets = new Map<string, ReplacementTarget[]>();
   {
     const betterLibFile = path.join(betterLibDir, `lib.${libFile}`);
@@ -198,43 +202,58 @@ function scanBetterFile(libFile: string): Map<string, ReplacementTarget[]> {
       // Scan better file to determine which statements need to be replaced.
       for (const statement of betterFile.statements) {
         const name = getStatementDeclName(statement) ?? "";
-        if (ts.isInterfaceDeclaration(statement)) {
-          const members = new Map<
-            string,
-            {
-              member: ts.TypeElement;
-              text: string;
-            }[]
-          >();
-          for (const member of statement.members) {
-            const memberName = member.name?.getText(betterFile) ?? "";
-            upsert(members, memberName, (members = []) => {
-              members.push({
-                member,
-                text: member.getFullText(betterFile),
+        const aliasesMap =
+          alias.get(name) ?? new Map([[name, new Map<string, string>()]]);
+        for (const [targetName, typeMap] of aliasesMap) {
+          const transformedStatement = replaceAliases(statement, typeMap);
+          if (ts.isInterfaceDeclaration(transformedStatement)) {
+            const members = new Map<
+              string,
+              {
+                member: ts.TypeElement;
+                text: string;
+              }[]
+            >();
+            for (const member of transformedStatement.members) {
+              const memberName = member.name?.getText(betterFile) ?? "";
+              upsert(members, memberName, (members = []) => {
+                const leadingSpacesMatch = /^\s*/.exec(
+                  member.getFullText(betterFile)
+                );
+                const leadingSpaces =
+                  leadingSpacesMatch !== null ? leadingSpacesMatch[0] : "";
+                members.push({
+                  member,
+                  text:
+                    leadingSpaces +
+                    printer.printNode(
+                      ts.EmitHint.Unspecified,
+                      member,
+                      betterFile
+                    ),
+                });
+                return members;
               });
-              return members;
-            });
-          }
-
-          upsert(replacementTargets, name, (targets = []) => {
-            targets.push({
-              type: "interface",
-              members,
-              originalStatement: statement,
-              sourceFile: betterFile,
+            }
+            upsert(replacementTargets, targetName, (targets = []) => {
+              targets.push({
+                type: "interface",
+                members,
+                originalStatement: transformedStatement,
+                sourceFile: betterFile,
+              });
+              return targets;
             });
-            return targets;
-          });
-        } else {
-          upsert(replacementTargets, name, (statements = []) => {
-            statements.push({
-              type: "non-interface",
-              statement,
-              sourceFile: betterFile,
+          } else {
+            upsert(replacementTargets, targetName, (statements = []) => {
+              statements.push({
+                type: "non-interface",
+                statement: transformedStatement,
+                sourceFile: betterFile,
+              });
+              return statements;
             });
-            return statements;
-          });
+          }
         }
       }
     }
@@ -372,3 +391,29 @@ function commentOut(code: string): string {
   const result = lines.map((line) => `// ${line}`);
   return result.join("\n") + "\n";
 }
+
+function replaceAliases(
+  statement: ts.Statement,
+  typeMap: Map<string, string>
+): ts.Statement {
+  if (typeMap.size === 0) return statement;
+  return ts.transform(statement, [
+    (context) => (sourceStatement) => {
+      const visitor = (node: ts.Node): ts.Node => {
+        if (ts.isTypeReferenceNode(node) && ts.isIdentifier(node.typeName)) {
+          const replacementType = typeMap.get(node.typeName.text);
+          if (replacementType === undefined) {
+            return node;
+          }
+          return ts.factory.updateTypeReferenceNode(
+            node,
+            ts.factory.createIdentifier(replacementType),
+            node.typeArguments
+          );
+        }
+        return ts.visitEachChild(node, visitor, context);
+      };
+      return ts.visitNode(sourceStatement, visitor);
+    },
+  ]).transformed[0];
+}

docs/diff.md

@@ -15,6 +15,7 @@ The following files are improved in better-typescript-lib:
 - [es2018.asyncgenerator.d.ts](./diff/es2018.asyncgenerator.d.ts.md)
 - [es2018.asynciterable.d.ts](./diff/es2018.asynciterable.d.ts.md)
 - [es2019.object.d.ts](./diff/es2019.object.d.ts.md)
+- [es2020.bigint.d.ts](./diff/es2020.bigint.d.ts.md)
 - [es2021.promise.d.ts](./diff/es2021.promise.d.ts.md)
 - [es2021.string.d.ts](./diff/es2021.string.d.ts.md)
 - [es2022.object.d.ts](./diff/es2022.object.d.ts.md)

docs/diff/es2015.collection.d.ts.md

@@ -13,7 +13,7 @@ Index: es2015.collection.d.ts
 -    callbackfn: (value: V, key: K, map: Map<K, V>) => void,
 -    thisArg?: any
 +  forEach<This = undefined>(
-+    callbackfn: (this: This, value: V, key: K, map: Map<K, V>) => void,
++    callbackfn: (this: This, value: V, key: K, map: this) => void,
 +    thisArg?: This
    ): void;
    get(key: K): V | undefined;
@@ -35,7 +35,7 @@ Index: es2015.collection.d.ts
 -    callbackfn: (value: V, key: K, map: ReadonlyMap<K, V>) => void,
 -    thisArg?: any
 +  forEach<This = undefined>(
-+    callbackfn: (this: This, value: V, key: K, map: ReadonlyMap<K, V>) => void,
++    callbackfn: (this: This, value: V, key: K, map: this) => void,
 +    thisArg?: This
    ): void;
    get(key: K): V | undefined;
@@ -66,7 +66,7 @@ Index: es2015.collection.d.ts
 -    callbackfn: (value: T, value2: T, set: Set<T>) => void,
 -    thisArg?: any
 +  forEach<This = undefined>(
-+    callbackfn: (this: This, value: T, value2: T, set: Set<T>) => void,
++    callbackfn: (this: This, value: T, value2: T, set: this) => void,
 +    thisArg?: This
    ): void;
    has(value: T): boolean;
@@ -86,7 +86,7 @@ Index: es2015.collection.d.ts
 -    callbackfn: (value: T, value2: T, set: ReadonlySet<T>) => void,
 -    thisArg?: any
 +  forEach<This = undefined>(
-+    callbackfn: (this: This, value: T, value2: T, set: ReadonlySet<T>) => void,
++    callbackfn: (this: This, value: T, value2: T, set: this) => void,
 +    thisArg?: This
    ): void;
    has(value: T): boolean;