From 6a467c2fa237cdc0053d9fb3c97efa6cb72c0f3b Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 18 Mar 2020 12:26:46 -0700
Subject: [PATCH 1/2] Add loose fuzzy matching for workspace symbol queries

---
 src/LanguageServer/Impl/Indexing/SymbolIndex.cs | 16 +++++++++++++++-
 src/LanguageServer/Test/SymbolIndexTests.cs     | 17 +++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/LanguageServer/Impl/Indexing/SymbolIndex.cs b/src/LanguageServer/Impl/Indexing/SymbolIndex.cs
index 7b97905b7..de913eff3 100644
--- a/src/LanguageServer/Impl/Indexing/SymbolIndex.cs
+++ b/src/LanguageServer/Impl/Indexing/SymbolIndex.cs
@@ -98,7 +98,7 @@ private IEnumerable<FlatSymbol> WorkspaceSymbolsQuery(string path, string query,
                 var sym = symAndPar.symbol;
                 return DecorateWithParentsName((sym.Children ?? Enumerable.Empty<HierarchicalSymbol>()).ToList(), sym.Name);
             });
-            return treeSymbols.Where(sym => sym.symbol.Name.ContainsOrdinal(query, ignoreCase: true))
+            return treeSymbols.Where(sym => FuzzyMatch(query, sym.symbol.Name))
                               .Select(sym => new FlatSymbol(sym.symbol.Name, sym.symbol.Kind, path, sym.symbol.SelectionRange, sym.parentName, sym.symbol._existInAllVariable));
         }
 
@@ -114,5 +114,19 @@ private IMostRecentDocumentSymbols MakeMostRecentDocSymbols(string path) {
         public void Dispose() {
             _disposables.TryDispose();
         }
+
+        private bool FuzzyMatch(string pattern, string name) {
+            var patternPos = 0;
+            var namePos = 0;
+
+            while (patternPos < pattern.Length && namePos < name.Length) {
+                if (char.ToLowerInvariant(pattern[patternPos]) == char.ToLowerInvariant(name[namePos])) {
+                    patternPos++;
+                }
+                namePos++;
+            }
+
+            return patternPos == pattern.Length;
+        }
     }
 }
diff --git a/src/LanguageServer/Test/SymbolIndexTests.cs b/src/LanguageServer/Test/SymbolIndexTests.cs
index 861eb1cec..d695ad8ce 100644
--- a/src/LanguageServer/Test/SymbolIndexTests.cs
+++ b/src/LanguageServer/Test/SymbolIndexTests.cs
@@ -160,6 +160,23 @@ public async Task IndexWorkspaceSymbolsCaseInsensitiveAsync() {
             }
         }
 
+        [TestMethod, Priority(0)]
+        public async Task IndexWorkspaceSymbolsFuzzyAsync() {
+            const string code = @"class FXoo(object):
+    def foxo(self, x): ...";
+
+            using (var index = MakeSymbolIndex()) {
+                var path = TestData.GetDefaultModulePath();
+                index.Add(path, DocumentWithAst(code));
+
+                var symbols = await index.WorkspaceSymbolsAsync("foo", maxSymbols);
+                symbols.Should().BeEquivalentToWithStrictOrdering(new[] {
+                    new FlatSymbol("FXoo", SymbolKind.Class, path, new SourceSpan(1, 7, 1, 11)),
+                    new FlatSymbol("foxo", SymbolKind.Method, path, new SourceSpan(2, 9, 2, 13), "FXoo"),
+                });
+            }
+        }
+
         [TestMethod, Priority(0)]
         public void MarkAsPendingWaitsForUpdates() {
             using (var index = MakeSymbolIndex()) {

From 38e1188dcd69bff223661dc9b43358eba03edbd8 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 18 Mar 2020 12:28:05 -0700
Subject: [PATCH 2/2] Make function static

---
 src/LanguageServer/Impl/Indexing/SymbolIndex.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/LanguageServer/Impl/Indexing/SymbolIndex.cs b/src/LanguageServer/Impl/Indexing/SymbolIndex.cs
index de913eff3..5d901f634 100644
--- a/src/LanguageServer/Impl/Indexing/SymbolIndex.cs
+++ b/src/LanguageServer/Impl/Indexing/SymbolIndex.cs
@@ -115,7 +115,7 @@ public void Dispose() {
             _disposables.TryDispose();
         }
 
-        private bool FuzzyMatch(string pattern, string name) {
+        private static bool FuzzyMatch(string pattern, string name) {
             var patternPos = 0;
             var namePos = 0;