Add isValidExpansion utility and refactor selection logic

Author: dandehoon

src/finders/line.ts

@@ -1,5 +1,6 @@
 import * as vscode from 'vscode';
 import { SelectionCandidate } from '../types';
+import { isValidExpansion } from './util';
 
 /**
  * Finds line expansion candidate that spans from start of line containing startIndex
@@ -42,7 +43,7 @@ export function findLineExpansion(
   const trimmedEnd = endLineEnd - trailingWhitespace;
 
   // Only return if it would expand the selection (not if selection already matches exactly)
-  if (startIndex === trimmedStart && endIndex === trimmedEnd) {
+  if (!isValidExpansion(startIndex, endIndex, trimmedStart, trimmedEnd)) {
     return null;
   }
 

src/finders/quote.ts

@@ -1,4 +1,5 @@
 import { SelectionCandidate } from '../types';
+import { isValidExpansion } from './util';
 
 /**
  * Finds all quote pairs (", ', `) and returns the nearest containing candidate
@@ -33,9 +34,12 @@ export function findNearestQuotePair(
 
             // Check if this candidate contains the current selection
             if (
-              startIndex >= candidate.start &&
-              endIndex <= candidate.end &&
-              !(startIndex === candidate.start && endIndex === candidate.end)
+              isValidExpansion(
+                startIndex,
+                endIndex,
+                candidate.start,
+                candidate.end,
+              )
             ) {
               // Keep track of the smallest containing candidate
               if (candidate.size < smallestSize) {

src/finders/scope.ts

@@ -1,4 +1,5 @@
 import { SelectionCandidate } from '../types';
+import { isValidExpansion } from './util';
 
 /**
  * Finds all balanced scopes ([], {}, (), <>) and returns the nearest containing candidate
@@ -36,9 +37,7 @@ export function findNearestScope(
 
         // Check if this candidate contains the current selection
         if (
-          startIndex >= candidate.start &&
-          endIndex <= candidate.end &&
-          !(startIndex === candidate.start && endIndex === candidate.end)
+          isValidExpansion(startIndex, endIndex, candidate.start, candidate.end)
         ) {
           // Keep track of the smallest containing candidate
           if (candidate.size < smallestSize) {

src/finders/token.ts

@@ -1,5 +1,6 @@
 import * as vscode from 'vscode';
 import { SelectionCandidate } from '../types';
+import { isValidExpansion } from './util';
 
 /**
  * Finds word boundaries using different regex patterns for extended token detection
@@ -20,7 +21,11 @@ export function findToken(
 
   // Define different word patterns to try
   const patterns = [
+    /[A-Z]?[a-z]+/, // With single word characters
+    /[a-zA-Z]+/, // With letters only
+    /[a-zA-Z0-9]+/, // With digits
     /[a-zA-Z0-9_]+/, // With underscores
+    /[a-zA-Z0-9_\-]+/, // Extended: includes underscores, dots, hyphens
     /[a-zA-Z0-9_\.\-]+/, // Extended: includes underscores, dots, hyphens
   ];
 
@@ -31,10 +36,7 @@ export function findToken(
       const wordEnd = document.offsetAt(wordRange.end);
 
       // Check if this would be a valid expansion
-      if (
-        (startIndex > wordStart || endIndex < wordEnd) &&
-        !(startIndex === wordStart && endIndex === wordEnd)
-      ) {
+      if (isValidExpansion(startIndex, endIndex, wordStart, wordEnd)) {
         return {
           start: wordStart,
           end: wordEnd,

src/finders/util.ts

@@ -0,0 +1,12 @@
+export function isValidExpansion(
+  startIndex: number,
+  endIndex: number,
+  rangeStart: number,
+  rangeEnd: number,
+): boolean {
+  return (
+    startIndex >= rangeStart &&
+    endIndex <= rangeEnd &&
+    !(startIndex === rangeStart && endIndex === rangeEnd)
+  );
+}