From 1e55d650f3dd8c768158c5a2bcde1ebf95b590a8 Mon Sep 17 00:00:00 2001
From: Wesley Wigham <wwigham@gmail.com>
Date: Tue, 2 Oct 2018 09:41:06 -0700
Subject: [PATCH] Exclude the overlap between Type and Value when checking for
 parameter visibility (#27444)

---
 src/compiler/checker.ts                                   | 2 +-
 .../reference/typeParameterDoesntBlockParameterLookup.js  | 4 ++++
 .../typeParameterDoesntBlockParameterLookup.symbols       | 8 ++++++++
 .../typeParameterDoesntBlockParameterLookup.types         | 5 +++++
 .../compiler/typeParameterDoesntBlockParameterLookup.ts   | 1 +
 5 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/typeParameterDoesntBlockParameterLookup.js
 create mode 100644 tests/baselines/reference/typeParameterDoesntBlockParameterLookup.symbols
 create mode 100644 tests/baselines/reference/typeParameterDoesntBlockParameterLookup.types
 create mode 100644 tests/cases/compiler/typeParameterDoesntBlockParameterLookup.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 6210ebcfbf8..82480428790 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -1238,7 +1238,7 @@ namespace ts {
                                     // local types not visible outside the function body
                                     : false;
                             }
-                            if (meaning & SymbolFlags.Value && result.flags & SymbolFlags.FunctionScopedVariable) {
+                            if (meaning & result.flags & SymbolFlags.FunctionScopedVariable) {
                                 // parameters are visible only inside function body, parameter list and return type
                                 // technically for parameter list case here we might mix parameters and variables declared in function,
                                 // however it is detected separately when checking initializers of parameters
diff --git a/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.js b/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.js
new file mode 100644
index 00000000000..90f1a1f4a37
--- /dev/null
+++ b/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.js
@@ -0,0 +1,4 @@
+//// [typeParameterDoesntBlockParameterLookup.ts]
+declare function f<Foo extends Bar, Bar>(Bar: any): void
+
+//// [typeParameterDoesntBlockParameterLookup.js]
diff --git a/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.symbols b/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.symbols
new file mode 100644
index 00000000000..8c98b05e2dd
--- /dev/null
+++ b/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.symbols
@@ -0,0 +1,8 @@
+=== tests/cases/compiler/typeParameterDoesntBlockParameterLookup.ts ===
+declare function f<Foo extends Bar, Bar>(Bar: any): void
+>f : Symbol(f, Decl(typeParameterDoesntBlockParameterLookup.ts, 0, 0))
+>Foo : Symbol(Foo, Decl(typeParameterDoesntBlockParameterLookup.ts, 0, 19))
+>Bar : Symbol(Bar, Decl(typeParameterDoesntBlockParameterLookup.ts, 0, 35), Decl(typeParameterDoesntBlockParameterLookup.ts, 0, 41))
+>Bar : Symbol(Bar, Decl(typeParameterDoesntBlockParameterLookup.ts, 0, 35), Decl(typeParameterDoesntBlockParameterLookup.ts, 0, 41))
+>Bar : Symbol(Bar, Decl(typeParameterDoesntBlockParameterLookup.ts, 0, 35), Decl(typeParameterDoesntBlockParameterLookup.ts, 0, 41))
+
diff --git a/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.types b/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.types
new file mode 100644
index 00000000000..7edcbde4373
--- /dev/null
+++ b/tests/baselines/reference/typeParameterDoesntBlockParameterLookup.types
@@ -0,0 +1,5 @@
+=== tests/cases/compiler/typeParameterDoesntBlockParameterLookup.ts ===
+declare function f<Foo extends Bar, Bar>(Bar: any): void
+>f : <Foo extends Bar, Bar>(Bar: any) => void
+>Bar : any
+
diff --git a/tests/cases/compiler/typeParameterDoesntBlockParameterLookup.ts b/tests/cases/compiler/typeParameterDoesntBlockParameterLookup.ts
new file mode 100644
index 00000000000..20db3123690
--- /dev/null
+++ b/tests/cases/compiler/typeParameterDoesntBlockParameterLookup.ts
@@ -0,0 +1 @@
+declare function f<Foo extends Bar, Bar>(Bar: any): void
\ No newline at end of file