3 files changed, 17 insertions, 8 deletions
diff --git a/plugin/AGENTS/ARCH.md b/plugin/AGENTS/ARCH.md
index 5242d3e..0f585bb 100644
--- a/plugin/AGENTS/ARCH.md
+++ b/plugin/AGENTS/ARCH.md
@@ -43,6 +43,9 @@ Source attribution is retained in `ThirdPartyNotices.md`.
 - `src/indentation.js` computes block depth from earlier lines and returns edits
   to leading whitespace only. A selection ending at column zero excludes that
   final line. Formatting is idempotent and preserves line endings and other text.
+  It also exports selection boundaries and on-type triggers for both editor adapters.
+  The Bundle imports this module, `lexical.js`, `brackets.js`, the grammar and
+  language configuration directly; keep these modules free of editor APIs.
 - `src/lexical.js` masks quotes and comments while preserving UTF-16 offsets.
 - `src/brackets.js` uses a stack to report unmatched opening and closing brackets
   and crossed types. Only invalid brackets receive the red decoration; native
diff --git a/plugin/src/extension.js b/plugin/src/extension.js
index 6bd1255..8fd5d22 100644
--- a/plugin/src/extension.js
+++ b/plugin/src/extension.js
@@ -1,8 +1,7 @@
 'use strict';
 
 const vscode = require('vscode');
-const { indentationEdits } = require('./indentation');
-const { codeOnly } = require('./lexical');
+const { indentationEdits, onTypeCharacters, shouldFormatOnType, selectionEndLine } = require('./indentation');
 const { unmatchedBrackets } = require('./brackets');
 const { registerRunner } = require('./runner');
 const languageId = 'cie-pseudocode';
@@ -42,18 +41,16 @@ function activate(context) {
 		vscode.window.onDidChangeVisibleTextEditors(() => refreshBrackets()),
 		vscode.languages.registerDocumentRangeFormattingEditProvider(languageId, {
 			provideDocumentRangeFormattingEdits(document, range) {
-				const endLine = range.end.character === 0 && range.end.line > range.start.line
-					? range.end.line - 1 : range.end.line;
+				const endLine = selectionEndLine(range.start.line, range.end.line, range.end.character);
 				return formatLines(document, range.start.line, endLine);
 			}
 		}),
 		vscode.languages.registerOnTypeFormattingEditProvider(languageId, {
 			provideOnTypeFormattingEdits(document, position, char) {
-				if (char !== '\n' && !/^\s*(?:ELSE|ENDIF|ENDWHILE|UNTIL|NEXT|ENDFUNCTION|ENDPROCEDURE|ENDTYPE|CATCH|ENDTRY)\b/.test(
-					codeOnly(document.lineAt(position.line).text))) return [];
+				if (!shouldFormatOnType(document.lineAt(position.line).text, char)) return [];
 				return formatLines(document, position.line, position.line, char === '\n');
 			}
-		}, '\n', 'E', 'F', 'L', 'T', 'N', 'H', 'Y')
+		}, ...onTypeCharacters)
 	);
 	refreshBrackets();
 }
diff --git a/plugin/src/indentation.js b/plugin/src/indentation.js
index b7fca78..fd3f585 100644
--- a/plugin/src/indentation.js
+++ b/plugin/src/indentation.js
@@ -1,6 +1,15 @@
 'use strict';
 
 const { codeOnly } = require('./lexical');
+const onTypeCharacters = ['\n', 'E', 'F', 'L', 'T', 'N', 'H', 'Y'];
+
+function shouldFormatOnType(line, character) {
+	return character === '\n' || /^\s*(?:ELSE|ENDIF|ENDWHILE|UNTIL|NEXT|ENDFUNCTION|ENDPROCEDURE|ENDTYPE|CATCH|ENDTRY)\b/.test(codeOnly(line));
+}
+
+function selectionEndLine(startLine, endLine, endColumn) {
+	return endColumn === 0 && endLine > startLine ? endLine - 1 : endLine;
+}
 const closers = {
 	ENDIF: 'IF', ENDWHILE: 'WHILE', UNTIL: 'REPEAT', NEXT: 'FOR',
 	ENDFUNCTION: 'FUNCTION', ENDPROCEDURE: 'PROCEDURE', ENDTYPE: 'TYPE', ENDTRY: 'TRY'
@@ -56,4 +65,4 @@ function indentationEdits(lines, startLine, endLine, keepBlankIndent = false) {
 	return edits;
 }
 
-module.exports = { lineDepths, indentationEdits };
+module.exports = { lineDepths, indentationEdits, onTypeCharacters, shouldFormatOnType, selectionEndLine };