From aa5c88f5a6c7751f23c4713b7ccd15f994b4b199 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Mon, 13 Feb 2017 14:42:51 -0800
Subject: [PATCH] Detect non-tag uses of `<` in TSX completions

---
 src/services/completions.ts                   | 30 ++++++++++++++-----
 .../fourslash/tsxCompletionNonTagLessThan.ts  | 14 +++++++++
 2 files changed, 37 insertions(+), 7 deletions(-)
 create mode 100644 tests/cases/fourslash/tsxCompletionNonTagLessThan.ts

diff --git a/src/services/completions.ts b/src/services/completions.ts
index df78ab931d..d5fe54df71 100644
--- a/src/services/completions.ts
+++ b/src/services/completions.ts
@@ -915,13 +915,29 @@ namespace ts.Completions {
                 }
             }
             else if (sourceFile.languageVariant === LanguageVariant.JSX) {
-                if (kind === SyntaxKind.LessThanToken) {
-                    isRightOfOpenTag = true;
-                    location = contextToken;
-                }
-                else if (kind === SyntaxKind.SlashToken && contextToken.parent.kind === SyntaxKind.JsxClosingElement) {
-                    isStartingCloseTag = true;
-                    location = contextToken;
+                switch (contextToken.parent.kind) {
+                    case SyntaxKind.JsxClosingElement:
+                        if (kind === SyntaxKind.SlashToken) {
+                            isStartingCloseTag = true;
+                            location = contextToken;
+                        }
+                        break;
+
+                    case SyntaxKind.BinaryExpression:
+                        if (!((contextToken.parent as BinaryExpression).left.flags & NodeFlags.ThisNodeHasError)) {
+                            // It has a left-hand side, so we're not in an opening JSX tag.
+                            break;
+                        }
+                        // fall through
+
+                    case SyntaxKind.JsxSelfClosingElement:
+                    case SyntaxKind.JsxElement:
+                    case SyntaxKind.JsxOpeningElement:
+                        if (kind === SyntaxKind.LessThanToken) {
+                            isRightOfOpenTag = true;
+                            location = contextToken;
+                        }
+                        break;
                 }
             }
         }
diff --git a/tests/cases/fourslash/tsxCompletionNonTagLessThan.ts b/tests/cases/fourslash/tsxCompletionNonTagLessThan.ts
new file mode 100644
index 0000000000..d40201146a
--- /dev/null
+++ b/tests/cases/fourslash/tsxCompletionNonTagLessThan.ts
@@ -0,0 +1,14 @@
+/// <reference path='fourslash.ts'/>
+
+////var x: Array<numb/*a*/;
+////[].map<numb/*b*/;
+////1 < Infini/*c*/;
+
+for (const marker of ["a", "b"]) {
+    goTo.marker(marker);
+    verify.completionListContains("number");
+    verify.not.completionListContains("SVGNumber");
+};
+
+goTo.marker("c");
+verify.completionListContains("Infinity");