BUILD PR: centralize codeToLetter across exact initials-entry batch.

Author: DavidQ

docs/dev/CODEX_COMMANDS.md

@@ -1 +1,11 @@
-Execute exactly. No expansion.
+MODEL: GPT-5.3-codex
+REASONING: high
+COMMAND:
+Execute docs/pr/BUILD_PR_SHARED_EXTRACTION_38_CODE_TO_LETTER_HIGHSCORE_BATCH.md exactly.
+Edit only these files:
+- src/shared/utils/initialsEntryUtils.js (new file)
+- games/Asteroids/systems/AsteroidsInitialsEntry.js
+- games/SpaceDuel/game/SpaceDuelInitialsEntry.js
+- games/SpaceInvaders/game/SpaceInvadersInitialsEntry.js
+Do not expand scope.
+Package the delta output to <project folder>/tmp/BUILD_PR_SHARED_EXTRACTION_38_CODE_TO_LETTER_HIGHSCORE_BATCH_delta.zip

docs/dev/COMMIT_COMMENT.txt

@@ -1 +1 @@
-BUILD_PR_SHARED_EXTRACTION_38_ID_UTILS_BATCH
+BUILD PR: centralize codeToLetter across exact initials-entry batch.

docs/dev/NEXT_COMMAND.txt

@@ -1 +1 @@
-Next batch
+Next: continue duplicate-family extraction from the provided duplicate report.

docs/dev/reports/change_summary.txt

@@ -1 +1 @@
-batch
+Execution-grade batch for codeToLetter using the exact duplicate-report file list.

docs/dev/reports/file_tree.txt

@@ -1 +1 @@
-docs
+docs only

docs/dev/reports/validation_checklist.txt

@@ -1 +1 @@
-validate
+Exact file list present; one PR purpose only; no guessing.

docs/pr/BUILD_PR_SHARED_EXTRACTION_38_CODE_TO_LETTER_HIGHSCORE_BATCH.md

@@ -0,0 +1,95 @@
+# BUILD_PR_SHARED_EXTRACTION_38_CODE_TO_LETTER_HIGHSCORE_BATCH
+
+## Purpose
+Centralize duplicated `codeToLetter(code)` implementations across the exact initials-entry batch identified in the duplicate report.
+
+## Single PR Purpose
+Normalize ONLY this helper:
+
+- `codeToLetter(code)`
+
+## Exact Files Allowed
+
+### New shared file
+1. `src/shared/utils/initialsEntryUtils.js`
+
+### Consumer files
+2. `games/Asteroids/systems/AsteroidsInitialsEntry.js`
+3. `games/SpaceDuel/game/SpaceDuelInitialsEntry.js`
+4. `games/SpaceInvaders/game/SpaceInvadersInitialsEntry.js`
+
+Do not edit any other file.
+
+## Source of Truth
+This exact scope comes from the provided duplicate report entry for:
+
+`function codeToLetter(code)`
+
+Only the 3 listed consumer files are in scope. fileciteturn8file0
+
+## Exact Shared Helper Creation
+Create:
+
+`src/shared/utils/initialsEntryUtils.js`
+
+Export exactly:
+
+```js
+export function codeToLetter(code) {
+  // copy one existing implementation exactly
+}
+```
+
+Implementation rules:
+- use ONE existing local implementation as source-of-truth
+- do NOT merge logic
+- do NOT generalize behavior
+- preserve the function signature exactly:
+  - `codeToLetter(code)`
+
+## Exact Consumer Changes
+For each of the 3 listed consumer files:
+
+If the file contains a local function definition matching:
+```js
+function codeToLetter(code)
+```
+then:
+- remove the local `codeToLetter(code)` function definition
+- import `codeToLetter` from the correct relative path to:
+  - `src/shared/utils/initialsEntryUtils.js`
+- if the file already imports from that module, add `codeToLetter` with the minimum safe edit
+- do not duplicate imports
+- do not touch unrelated helpers
+- do not change logic
+
+If a listed file already imports and uses shared `codeToLetter`, leave it unchanged.
+
+## Relative Import Rule
+Use the correct relative path from each consumer file to:
+
+`src/shared/utils/initialsEntryUtils.js`
+
+Do not use aliases.
+Do not change `.js` extension usage.
+
+## Hard Constraints
+- no engine changes
+- no game files outside the 3 listed consumers
+- no sample files
+- no repo-wide initials helper cleanup
+- no behavior changes
+- keep one PR purpose only
+
+## Validation Checklist
+1. Confirm no more than the 4 listed files changed
+2. Confirm `src/shared/utils/initialsEntryUtils.js` exists and exports `codeToLetter`
+3. Confirm local `function codeToLetter(code)` definitions no longer exist in changed listed consumer files
+4. Confirm changed consumer files import `codeToLetter` from the correct relative path to `src/shared/utils/initialsEntryUtils.js`
+5. Confirm no unrelated engine, game, or sample files changed
+6. Confirm no behavior changes were made
+
+## Non-Goals
+- no cleanup of high score service helpers in this PR
+- no cleanup outside the 3 listed consumer files
+- no refactor beyond this exact duplicate-removal batch

games/Asteroids/systems/AsteroidsInitialsEntry.js

@@ -4,16 +4,9 @@ David Quesenberry
 03/25/2026
 AsteroidsInitialsEntry.js
 */
-const KEY_CODES = Array.from({ length: 26 }).map((_, index) => `Key${String.fromCharCode(65 + index)}`);
-
-function codeToLetter(code) {
-  if (!code || !code.startsWith('Key')) {
-    return null;
-  }
+import { codeToLetter } from '../../../src/shared/utils/initialsEntryUtils.js';
 
-  const letter = code.slice(3, 4).toUpperCase();
-  return /^[A-Z]$/.test(letter) ? letter : null;
-}
+const KEY_CODES = Array.from({ length: 26 }).map((_, index) => `Key${String.fromCharCode(65 + index)}`);
 
 export default class AsteroidsInitialsEntry {
   constructor() {

games/SpaceDuel/game/SpaceDuelInitialsEntry.js

@@ -4,16 +4,9 @@ David Quesenberry
 03/25/2026
 SpaceDuelInitialsEntry.js
 */
-const KEY_CODES = Array.from({ length: 26 }).map((_, index) => `Key${String.fromCharCode(65 + index)}`);
-
-function codeToLetter(code) {
-  if (!code || !code.startsWith('Key')) {
-    return null;
-  }
+import { codeToLetter } from '../../../src/shared/utils/initialsEntryUtils.js';
 
-  const letter = code.slice(3, 4).toUpperCase();
-  return /^[A-Z]$/.test(letter) ? letter : null;
-}
+const KEY_CODES = Array.from({ length: 26 }).map((_, index) => `Key${String.fromCharCode(65 + index)}`);
 
 export default class SpaceDuelInitialsEntry {
   constructor() {

games/SpaceInvaders/game/SpaceInvadersInitialsEntry.js

@@ -4,16 +4,9 @@ David Quesenberry
 03/25/2026
 SpaceInvadersInitialsEntry.js
 */
-const KEY_CODES = Array.from({ length: 26 }).map((_, index) => `Key${String.fromCharCode(65 + index)}`);
-
-function codeToLetter(code) {
-  if (!code || !code.startsWith('Key')) {
-    return null;
-  }
+import { codeToLetter } from '../../../src/shared/utils/initialsEntryUtils.js';
 
-  const letter = code.slice(3, 4).toUpperCase();
-  return /^[A-Z]$/.test(letter) ? letter : null;
-}
+const KEY_CODES = Array.from({ length: 26 }).map((_, index) => `Key${String.fromCharCode(65 + index)}`);
 
 export default class SpaceInvadersInitialsEntry {
   constructor() {