fix(highlight): don't highlight all words when querying .*

Assume good faith: a user wanted to highlight all words, this is not DOS hardening.

Issue 40

Author: david-allison

CorpusSearch.Test/HighlightingTest.cs

@@ -189,6 +189,19 @@ public void CountsAreUnchangedByHighlighting()
         Assert.That(result.Lines.Select(x => x.MatchesInLine), Is.EquivalentTo(new long?[] { 2, 1 }));
     }
 
+    [Test]
+    public void WildcardOnlyQueriesBrowseInsteadOfHighlightingEveryToken(
+        [Values("*", " * ", ".*", ",*", "*.", "**")] string query)
+    {
+        // '.*' normalizes to '*' and previously bypassed the browse short-circuit,
+        // matching (and highlighting) every token of every line
+        this.AddManxDoc(DOC, "Ta çhengey aym", "gyn veg");
+        var result = SearchWork(query);
+        Assert.That(result.Lines, Has.Count.EqualTo(2));
+        Assert.That(result.TotalMatches, Is.Null, "browse results have no match count");
+        Assert.That(result.Lines.Select(x => x.ManxHighlights), Is.All.Null);
+    }
+
     private ScanResult Scan(string query, ScanOptions options = null)
     {
         return new Searcher(luceneIndex, parser).Scan(query, options ?? ScanOptions.Default);

CorpusSearch/Dependencies/Searcher.cs

@@ -17,7 +17,13 @@ public class Searcher(LuceneIndex luceneIndex, SearchParser parser)
 
     internal SearchResult SearchWork(string ident, string query, SearchOptions options)
     {
-        if (query.Trim() == "*")
+        // HACK: use the ScanOptions as they're the same for now
+        var scanOptionsHack = new ScanOptions { SearchType = options.Type };
+
+        // Detect '*' on the normalized*query to handle '.*'.
+        // Intended for good faith use, not security hardening.
+        var normalizedQuery = GetTerm(query, scanOptionsHack);
+        if (normalizedQuery.Length > 0 && normalizedQuery.All(x => x == '*'))
         {
             return new SearchResult
             {
@@ -26,8 +32,6 @@ internal SearchResult SearchWork(string ident, string query, SearchOptions optio
                 TotalMatches = null,
             };
         }
-        // HACK: use the ScanOptions as they're the same for now
-        var scanOptionsHack = new ScanOptions { SearchType = options.Type };
 
         // parse the string into a Result<Expression>
         var parsed = parser.Parse(query);