double quotes inclusion

lib/text-highlight.ts

@@ -49,6 +49,26 @@ function normalizeQuotes(s: string): string {
     .replace(/[‘’‚‛′]/g, "'");
 }
 
+// Strip IAST / Vedic diacritics for matching. Decomposes via NFD then drops
+// codepoints in the Combining Diacritical Marks block. Necessary because
+// Typesense returns snippets from the `_ascii` shadow field (e.g. "Krsna")
+// while the rendered DOM uses the original IAST form ("Kṛṣṇa") — without
+// this normalization, a search-result link to KB 1.34 with prefix "Krsna is
+// so beautiful" never matches the "Kṛṣṇa is so beautiful" in the DOM.
+//
+// Length-preserving for NFC input (one NFC char → one ASCII char): NFD
+// expands an accented char into base + combining mark, the regex deletes
+// only the combining mark, and the base is left. So position maps built
+// from the original collapsed string remain valid after this transform.
+function stripDiacritics(s: string): string {
+  return s.normalize("NFD").replace(/[̀-ͯ]/g, "");
+}
+
+// Combined normalization used on both sides of every match.
+function normalizeForMatch(s: string): string {
+  return stripDiacritics(normalizeQuotes(s.toLowerCase()));
+}
+
 /**
  * Decode a text fragment from URL params.
  * Supports `§` (current), `|` (v2 legacy), and `,` (v1 legacy) delimiters.
@@ -103,10 +123,10 @@ export function extractMatchedText(
   // Build a single string with paragraph breaks
   const fullText = plainParagraphs.join(" ");
   const normalized = fullText.replace(/\s+/g, " ");
-  const normalizedLower = normalizeQuotes(normalized.toLowerCase());
+  const normalizedLower = normalizeForMatch(normalized);
 
-  const normalizedPrefix = normalizeQuotes(
+  const normalizedPrefix = normalizeForMatch(
-    fragment.prefix.replace(/\s+/g, " ").toLowerCase(),
+    fragment.prefix.replace(/\s+/g, " "),
   );
   let searchFrom = 0;
   let matchStart = -1;
@@ -116,8 +136,8 @@ export function extractMatchedText(
     if (idx === -1) break;
 
     if (fragment.suffix) {
-      const normalizedSuffix = normalizeQuotes(
+      const normalizedSuffix = normalizeForMatch(
-        fragment.suffix.replace(/\s+/g, " ").toLowerCase(),
+        fragment.suffix.replace(/\s+/g, " "),
       );
       const expectedEnd = idx + fragment.length;
       const suffixSearchStart = Math.max(
@@ -397,15 +417,15 @@ export function findAndHighlightText(fragment: {
     }
   }
 
-  // Quote-normalize for matching so the prefix/suffix and the DOM text agree
+  // Normalize for matching so prefix/suffix and DOM text agree on quote style
-  // even when one side uses straight ASCII quotes and the other uses curly
+  // and diacritics (search snippets come from the `_ascii` shadow field, the
-  // typographical quotes. Length-preserving, so collapsedPosMap indices stay
+  // DOM renders the original IAST form). Length-preserving for NFC input, so
-  // valid against rawText.
+  // collapsedPosMap indices remain valid against rawText.
-  const normalizedFullLower = normalizeQuotes(collapsedNorm.toLowerCase());
+  const normalizedFullLower = normalizeForMatch(collapsedNorm);
 
   // Search for the prefix in the full text (case-insensitive)
-  const normalizedPrefix = normalizeQuotes(
+  const normalizedPrefix = normalizeForMatch(
-    fragment.prefix.replace(/\s+/g, " ").toLowerCase(),
+    fragment.prefix.replace(/\s+/g, " "),
   );
   let searchFrom = 0;
   let matchStartNorm = -1;
@@ -416,8 +436,8 @@ export function findAndHighlightText(fragment: {
 
     // If we have a suffix, verify it appears near the expected length
     if (fragment.suffix) {
-      const normalizedSuffix = normalizeQuotes(
+      const normalizedSuffix = normalizeForMatch(
-        fragment.suffix.replace(/\s+/g, " ").toLowerCase(),
+        fragment.suffix.replace(/\s+/g, " "),
       );
       // Search for suffix near the expected end position in the normalized string.
       // Use a wider tolerance window (±50) since normalization can shift positions.