feat(create-gen-app): switch placeholders to four underscores

- treat variables as ____VAR____ throughout extraction, prompts, and README
- add automatic normalization for question names using ____VAR____ or legacy __VAR__
- extend ignore logic to cover content tokens by default
- update unit tests for new placeholder format

Author: sdqede

packages/create-gen-app/README.md

@@ -19,7 +19,7 @@ A TypeScript library for cloning and customizing template repositories with vari
 ## Features
 
 - Clone GitHub repositories or any git URL
-- Extract template variables from filenames and file contents using `__VARIABLE__` syntax
+- Extract template variables from filenames and file contents using `____VARIABLE____` syntax
 - Load custom questions from `.questions.json` or `.questions.js` files
 - Interactive prompts using inquirerer with CLI argument support
 - Stream-based file processing for efficient variable replacement
@@ -49,19 +49,19 @@ await createGen({
 
 ### Template Variables
 
-Variables in your template should be wrapped in double underscores:
+Variables in your template should be wrapped in `____` (four underscores) on both sides:
 
 **Filename variables:**
 ```
-__PROJECT_NAME__/
-  __MODULE_NAME__.ts
+____PROJECT_NAME____/
+  ____MODULE_NAME____.ts
 ```
 
 **Content variables:**
 ```typescript
-// __MODULE_NAME__.ts
-export const projectName = "__PROJECT_NAME__";
-export const author = "__AUTHOR__";
+// ____MODULE_NAME____.ts
+export const projectName = "____PROJECT_NAME____";
+export const author = "____AUTHOR____";
 ```
 
 ### Custom Questions

packages/create-gen-app/__tests__/create-gen.test.ts

@@ -45,10 +45,10 @@ describe("create-gen-app", () => {
   describe("extractVariables", () => {
     it("should extract variables from filenames", async () => {
       fs.writeFileSync(
-        path.join(testTempDir, "__PROJECT_NAME__.txt"),
+        path.join(testTempDir, "____PROJECT_NAME____.txt"),
         "content"
       );
-      fs.writeFileSync(path.join(testTempDir, "__AUTHOR__.md"), "content");
+      fs.writeFileSync(path.join(testTempDir, "____AUTHOR____.md"), "content");
 
       const result = await extractVariables(testTempDir);
 
@@ -62,7 +62,7 @@ describe("create-gen-app", () => {
     it("should extract variables from file contents", async () => {
       fs.writeFileSync(
         path.join(testTempDir, "test.txt"),
-        "Hello __USER_NAME__, welcome to __PROJECT_NAME__!"
+        "Hello ____USER_NAME____, welcome to ____PROJECT_NAME____!"
       );
 
       const result = await extractVariables(testTempDir);
@@ -77,11 +77,11 @@ describe("create-gen-app", () => {
     });
 
     it("should extract variables from nested directories", async () => {
-      const nestedDir = path.join(testTempDir, "src", "__MODULE_NAME__");
+      const nestedDir = path.join(testTempDir, "src", "____MODULE_NAME____");
       fs.mkdirSync(nestedDir, { recursive: true });
       fs.writeFileSync(
-        path.join(nestedDir, "__FILE_NAME__.ts"),
-        'export const __CONSTANT__ = "value";'
+        path.join(nestedDir, "____FILE_NAME____.ts"),
+        'export const ____CONSTANT____ = "value";'
       );
 
       const result = await extractVariables(testTempDir);
@@ -163,7 +163,7 @@ module.exports = {
     it("should skip .questions.json and .questions.js from variable extraction", async () => {
       fs.writeFileSync(
         path.join(testTempDir, ".questions.json"),
-        '{"questions": [{"name": "__SHOULD_NOT_EXTRACT__"}]}'
+        '{"questions": [{"name": "____SHOULD_NOT_EXTRACT____"}]}'
       );
 
       const result = await extractVariables(testTempDir);
@@ -176,7 +176,7 @@ module.exports = {
     it("should handle variables with different casings", async () => {
       fs.writeFileSync(
         path.join(testTempDir, "test.txt"),
-        "__lowercase__ __UPPERCASE__ __CamelCase__ __snake_case__"
+        "__lowercase__ ____UPPERCASE____ ____CamelCase____ __snake_case__"
       );
 
       const result = await extractVariables(testTempDir);
@@ -210,9 +210,9 @@ module.exports = {
 
       const extractedVariables: ExtractedVariables = {
         fileReplacers: [
-          { variable: "PROJECT_NAME", pattern: /__PROJECT_NAME__/g },
+          { variable: "PROJECT_NAME", pattern: /____PROJECT_NAME____/g },
         ],
-        contentReplacers: [{ variable: "AUTHOR", pattern: /__AUTHOR__/g }],
+        contentReplacers: [{ variable: "AUTHOR", pattern: /____AUTHOR____/g }],
         projectQuestions: null,
       };
 
@@ -272,7 +272,7 @@ module.exports = {
 
       const extractedVariables: ExtractedVariables = {
         fileReplacers: [
-          { variable: "PROJECT_NAME", pattern: /__PROJECT_NAME__/g },
+          { variable: "PROJECT_NAME", pattern: /____PROJECT_NAME____/g },
         ],
         contentReplacers: [],
         projectQuestions: null,
@@ -289,7 +289,7 @@ module.exports = {
     it("should replace variables in file contents", async () => {
       fs.writeFileSync(
         path.join(testTempDir, "README.md"),
-        "# __PROJECT_NAME__\n\nBy __AUTHOR__"
+        "# ____PROJECT_NAME____\n\nBy ____AUTHOR____"
       );
 
       const extractedVariables = await extractVariables(testTempDir);
@@ -315,7 +315,7 @@ module.exports = {
 
     it("should replace variables in filenames", async () => {
       fs.writeFileSync(
-        path.join(testTempDir, "__PROJECT_NAME__.config.js"),
+        path.join(testTempDir, "____PROJECT_NAME____.config.js"),
         "module.exports = {};"
       );
 
@@ -338,11 +338,11 @@ module.exports = {
     });
 
     it("should replace variables in nested directory names", async () => {
-      const nestedDir = path.join(testTempDir, "src", "__MODULE_NAME__");
+      const nestedDir = path.join(testTempDir, "src", "____MODULE_NAME____");
       fs.mkdirSync(nestedDir, { recursive: true });
       fs.writeFileSync(
         path.join(nestedDir, "index.ts"),
-        'export const name = "__MODULE_NAME__";'
+        'export const name = "____MODULE_NAME____";'
       );
 
       const extractedVariables = await extractVariables(testTempDir);
@@ -389,7 +389,7 @@ module.exports = {
     it("should handle multiple occurrences of the same variable", async () => {
       fs.writeFileSync(
         path.join(testTempDir, "test.txt"),
-        "__NAME__ loves __NAME__ and __NAME__ is great!"
+        "____NAME____ loves ____NAME____ and ____NAME____ is great!"
       );
 
       const extractedVariables = await extractVariables(testTempDir);
@@ -450,7 +450,7 @@ module.exports = {
     fs.mkdirSync(ignoredDir);
     fs.writeFileSync(
       path.join(ignoredDir, "example.txt"),
-      "This file has __IGNORED__ variable"
+      "This file has ____IGNORED____ variable"
     );
     fs.writeFileSync(
       path.join(testTempDir, ".questions.json"),

packages/create-gen-app/src/extract.ts

@@ -8,10 +8,15 @@ import {
   Questions,
 } from "./types";
 
+const PLACEHOLDER_BOUNDARY = "____";
+
 /**
- * Pattern to match __VARIABLE__ in filenames and content
+ * Pattern to match ____VARIABLE____ in filenames and content
  */
-const VARIABLE_PATTERN = /__([A-Za-z_][A-Za-z0-9_]*)__/g;
+const VARIABLE_PATTERN = new RegExp(
+  `${PLACEHOLDER_BOUNDARY}([A-Za-z_][A-Za-z0-9_]*)${PLACEHOLDER_BOUNDARY}`,
+  "g"
+);
 
 /**
  * Extract all variables from a template directory
@@ -27,11 +32,12 @@ export async function extractVariables(
   const contentReplacerVars = new Set<string>();
 
   const projectQuestions = await loadProjectQuestions(templateDir);
-  const ignoredPatterns = new Set<string>(projectQuestions?.ignore ?? []);
+  const ignoredPathPatterns = new Set<string>(projectQuestions?.ignore ?? []);
+  const ignoredContentTokens = buildIgnoredContentTokens(projectQuestions);
 
   await walkDirectory(templateDir, async (filePath) => {
     const relativePath = path.relative(templateDir, filePath);
-    if (shouldIgnore(relativePath, ignoredPatterns)) {
+    if (shouldIgnore(relativePath, ignoredPathPatterns)) {
       return;
     }
 
@@ -49,18 +55,27 @@ export async function extractVariables(
         fileReplacerVars.add(varName);
         fileReplacers.push({
           variable: varName,
-          pattern: new RegExp(`__${varName}__`, "g"),
+          pattern: new RegExp(
+            `${PLACEHOLDER_BOUNDARY}${varName}${PLACEHOLDER_BOUNDARY}`,
+            "g"
+          ),
         });
       }
     }
 
-    const contentVars = await extractFromFileContent(filePath, ignoredPatterns);
+    const contentVars = await extractFromFileContent(
+      filePath,
+      ignoredContentTokens
+    );
     for (const varName of contentVars) {
       if (!contentReplacerVars.has(varName)) {
         contentReplacerVars.add(varName);
         contentReplacers.push({
           variable: varName,
-          pattern: new RegExp(`__${varName}__`, "g"),
+          pattern: new RegExp(
+            `${PLACEHOLDER_BOUNDARY}${varName}${PLACEHOLDER_BOUNDARY}`,
+            "g"
+          ),
         });
       }
     }
@@ -80,7 +95,7 @@ export async function extractVariables(
  */
 async function extractFromFileContent(
   filePath: string,
-  ignoredPatterns: Set<string>
+  ignoredTokens: Set<string>
 ): Promise<Set<string>> {
   const variables = new Set<string>();
 
@@ -97,7 +112,7 @@ async function extractFromFileContent(
       for (const line of lines) {
         const matches = line.matchAll(VARIABLE_PATTERN);
         for (const match of matches) {
-          if (!shouldIgnoreContent(match[0], ignoredPatterns)) {
+          if (!shouldIgnoreContent(match[0], ignoredTokens)) {
             variables.add(match[1]);
           }
         }
@@ -107,7 +122,7 @@ async function extractFromFileContent(
     stream.on("end", () => {
       const matches = buffer.matchAll(VARIABLE_PATTERN);
       for (const match of matches) {
-        if (!shouldIgnoreContent(match[0], ignoredPatterns)) {
+        if (!shouldIgnoreContent(match[0], ignoredTokens)) {
           variables.add(match[1]);
         }
       }
@@ -226,22 +241,49 @@ function shouldIgnore(
   return false;
 }
 
-const DEFAULT_IGNORED_CONTENT = new Set(["__tests__", "__snapshots__"]);
+const DEFAULT_IGNORED_CONTENT_TOKENS = ["tests", "snapshots"];
 
 function shouldIgnoreContent(
   match: string,
-  ignoredPatterns: Set<string>
+  ignoredTokens: Set<string>
 ): boolean {
-  if (ignoredPatterns.size === 0 && DEFAULT_IGNORED_CONTENT.size === 0) {
+  if (ignoredTokens.size === 0) {
     return false;
   }
-  const normalizedMatch = match.slice(2, -2);
-  return (
-    ignoredPatterns.has(match) ||
-    ignoredPatterns.has(normalizedMatch) ||
-    DEFAULT_IGNORED_CONTENT.has(match) ||
-    DEFAULT_IGNORED_CONTENT.has(normalizedMatch)
+  const token = match.slice(
+    PLACEHOLDER_BOUNDARY.length,
+    -PLACEHOLDER_BOUNDARY.length
   );
+  return ignoredTokens.has(token);
+}
+
+function buildIgnoredContentTokens(projectQuestions: Questions | null): Set<string> {
+  const tokens = new Set<string>(DEFAULT_IGNORED_CONTENT_TOKENS);
+  if (projectQuestions?.ignore) {
+    for (const entry of projectQuestions.ignore) {
+      const normalized = normalizePlaceholder(entry);
+      if (normalized) {
+        tokens.add(normalized);
+      }
+    }
+  }
+  return tokens;
+}
+
+function normalizePlaceholder(entry: string): string | null {
+  if (
+    entry.startsWith(PLACEHOLDER_BOUNDARY) &&
+    entry.endsWith(PLACEHOLDER_BOUNDARY)
+  ) {
+    return entry.slice(
+      PLACEHOLDER_BOUNDARY.length,
+      -PLACEHOLDER_BOUNDARY.length
+    );
+  }
+  if (entry.startsWith("__") && entry.endsWith("__")) {
+    return entry.slice(2, -2);
+  }
+  return entry || null;
 }
 
 /**

packages/create-gen-app/src/prompt.ts

@@ -1,13 +1,17 @@
-import { Inquirerer, Question } from 'inquirerer';
+import { Inquirerer, Question } from "inquirerer";
 
-import { ExtractedVariables } from './types';
+import { ExtractedVariables } from "./types";
+
+const PLACEHOLDER_BOUNDARY = "____";
 
 /**
  * Generate questions from extracted variables
  * @param extractedVariables - Variables extracted from the template
  * @returns Array of questions to prompt the user
  */
-export function generateQuestions(extractedVariables: ExtractedVariables): Question[] {
+export function generateQuestions(
+  extractedVariables: ExtractedVariables
+): Question[] {
   const questions: Question[] = [];
   const askedVariables = new Set<string>();
 
@@ -48,7 +52,16 @@ export function generateQuestions(extractedVariables: ExtractedVariables): Quest
 }
 
 function normalizeQuestionName(name: string): string {
-  if (/^__.+__$/.test(name)) {
+  if (
+    name.startsWith(PLACEHOLDER_BOUNDARY) &&
+    name.endsWith(PLACEHOLDER_BOUNDARY)
+  ) {
+    return name.slice(
+      PLACEHOLDER_BOUNDARY.length,
+      -PLACEHOLDER_BOUNDARY.length
+    );
+  }
+  if (name.startsWith("__") && name.endsWith("__")) {
     return name.slice(2, -2);
   }
   return name;

packages/create-gen-app/src/types.ts

@@ -11,15 +11,15 @@ export interface Questions {
 }
 
 /**
- * Variable extracted from filename patterns like __VARIABLE__
+ * Variable extracted from filename patterns like ____VARIABLE____
  */
 export interface FileReplacer {
   variable: string;
   pattern: RegExp;
 }
 
 /**
- * Variable extracted from file content patterns like __VARIABLE__
+ * Variable extracted from file content patterns like ____VARIABLE____
  */
 export interface ContentReplacer {
   variable: string;