From 7b1147fbcefbd67fb0a790e6ac54a7e93c94d8f8 Mon Sep 17 00:00:00 2001
From: Andrew Casey <andrew.casey@microsoft.com>
Date: Tue, 3 Oct 2017 12:23:32 -0700
Subject: [PATCH] Stop inadvertently exempting expression statements from check

---
 src/harness/unittests/extractConstants.ts         |  7 +++++++
 src/services/refactors/extractSymbol.ts           | 15 +++++++--------
 ...ctConstant_ExpressionStatementConsumesLocal.js | 14 ++++++++++++++
 ...ctConstant_ExpressionStatementConsumesLocal.ts | 14 ++++++++++++++
 4 files changed, 42 insertions(+), 8 deletions(-)
 create mode 100644 tests/baselines/reference/extractConstant/extractConstant_ExpressionStatementConsumesLocal.js
 create mode 100644 tests/baselines/reference/extractConstant/extractConstant_ExpressionStatementConsumesLocal.ts

diff --git a/src/harness/unittests/extractConstants.ts b/src/harness/unittests/extractConstants.ts
index b58016cd56f..63a150856f5 100644
--- a/src/harness/unittests/extractConstants.ts
+++ b/src/harness/unittests/extractConstants.ts
@@ -40,6 +40,13 @@ function F() {
 }
         `);
 
+        testExtractConstant("extractConstant_ExpressionStatementConsumesLocal", `
+function F() {
+    let i = 0;
+    [#|i++|];
+}
+        `);
+
         testExtractConstant("extractConstant_BlockScopes_NoDependencies",
             `for (let i = 0; i < 10; i++) {
     for (let j = 0; j < 10; j++) {
diff --git a/src/services/refactors/extractSymbol.ts b/src/services/refactors/extractSymbol.ts
index a7646f6234e..9e2ca3da4f7 100644
--- a/src/services/refactors/extractSymbol.ts
+++ b/src/services/refactors/extractSymbol.ts
@@ -1351,14 +1351,13 @@ namespace ts.refactor.extractSymbol {
         }
 
         for (let i = 0; i < scopes.length; i++) {
-            if (!isReadonlyArray(targetRange.range)) {
-                const scopeUsages = usagesPerScope[i];
-                // Special case: in the innermost scope, all usages are available.
-                // (The computed value reflects the value at the top-level of the scope, but the
-                // local will actually be declared at the same level as the extracted expression).
-                if (i > 0 && (scopeUsages.usages.size > 0 || scopeUsages.typeParameterUsages.size > 0)) {
-                    constantErrorsPerScope[i].push(createDiagnosticForNode(targetRange.range, Messages.CannotAccessVariablesFromNestedScopes));
-                }
+            const scopeUsages = usagesPerScope[i];
+            // Special case: in the innermost scope, all usages are available.
+            // (The computed value reflects the value at the top-level of the scope, but the
+            // local will actually be declared at the same level as the extracted expression).
+            if (i > 0 && (scopeUsages.usages.size > 0 || scopeUsages.typeParameterUsages.size > 0)) {
+                const errorNode = isReadonlyArray(targetRange.range) ? targetRange.range[0] : targetRange.range;
+                constantErrorsPerScope[i].push(createDiagnosticForNode(errorNode, Messages.CannotAccessVariablesFromNestedScopes));
             }
 
             let hasWrite = false;
diff --git a/tests/baselines/reference/extractConstant/extractConstant_ExpressionStatementConsumesLocal.js b/tests/baselines/reference/extractConstant/extractConstant_ExpressionStatementConsumesLocal.js
new file mode 100644
index 00000000000..b57da0d8e8c
--- /dev/null
+++ b/tests/baselines/reference/extractConstant/extractConstant_ExpressionStatementConsumesLocal.js
@@ -0,0 +1,14 @@
+// ==ORIGINAL==
+
+function F() {
+    let i = 0;
+    i++;
+}
+        
+// ==SCOPE::Extract to constant in enclosing scope==
+
+function F() {
+    let i = 0;
+    const /*RENAME*/newLocal = i++;
+}
+        
\ No newline at end of file
diff --git a/tests/baselines/reference/extractConstant/extractConstant_ExpressionStatementConsumesLocal.ts b/tests/baselines/reference/extractConstant/extractConstant_ExpressionStatementConsumesLocal.ts
new file mode 100644
index 00000000000..b57da0d8e8c
--- /dev/null
+++ b/tests/baselines/reference/extractConstant/extractConstant_ExpressionStatementConsumesLocal.ts
@@ -0,0 +1,14 @@
+// ==ORIGINAL==
+
+function F() {
+    let i = 0;
+    i++;
+}
+        
+// ==SCOPE::Extract to constant in enclosing scope==
+
+function F() {
+    let i = 0;
+    const /*RENAME*/newLocal = i++;
+}
+        
\ No newline at end of file