From 518be067e440b6df58b2814bdce3bfadef071545 Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Fri, 6 Nov 2020 15:43:22 +0200
Subject: [PATCH] fix(41240): allow emitting numeric with underscored
 separators as-is in esnext target

---
 src/compiler/emitter.ts                        |  3 ++-
 src/compiler/utilities.ts                      | 18 ++++++++++++++----
 ...mericUnderscoredSeparator(target=es2015).js | 12 ++++++++++++
 ...UnderscoredSeparator(target=es2015).symbols |  7 +++++++
 ...icUnderscoredSeparator(target=es2015).types | 13 +++++++++++++
 ...mericUnderscoredSeparator(target=es2016).js | 12 ++++++++++++
 ...UnderscoredSeparator(target=es2016).symbols |  7 +++++++
 ...icUnderscoredSeparator(target=es2016).types | 13 +++++++++++++
 ...mericUnderscoredSeparator(target=es2017).js | 12 ++++++++++++
 ...UnderscoredSeparator(target=es2017).symbols |  7 +++++++
 ...icUnderscoredSeparator(target=es2017).types | 13 +++++++++++++
 ...mericUnderscoredSeparator(target=es2018).js | 12 ++++++++++++
 ...UnderscoredSeparator(target=es2018).symbols |  7 +++++++
 ...icUnderscoredSeparator(target=es2018).types | 13 +++++++++++++
 ...mericUnderscoredSeparator(target=es2019).js | 12 ++++++++++++
 ...UnderscoredSeparator(target=es2019).symbols |  7 +++++++
 ...icUnderscoredSeparator(target=es2019).types | 13 +++++++++++++
 .../numericUnderscoredSeparator(target=es3).js | 12 ++++++++++++
 ...ricUnderscoredSeparator(target=es3).symbols |  7 +++++++
 ...mericUnderscoredSeparator(target=es3).types | 13 +++++++++++++
 .../numericUnderscoredSeparator(target=es5).js | 12 ++++++++++++
 ...ricUnderscoredSeparator(target=es5).symbols |  7 +++++++
 ...mericUnderscoredSeparator(target=es5).types | 13 +++++++++++++
 ...mericUnderscoredSeparator(target=esnext).js | 12 ++++++++++++
 ...UnderscoredSeparator(target=esnext).symbols |  7 +++++++
 ...icUnderscoredSeparator(target=esnext).types | 13 +++++++++++++
 .../compiler/numericUnderscoredSeparator.ts    |  6 ++++++
 27 files changed, 278 insertions(+), 5 deletions(-)
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2015).js
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2015).symbols
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2015).types
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2016).js
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2016).symbols
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2016).types
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2017).js
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2017).symbols
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2017).types
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2018).js
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2018).symbols
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2018).types
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2019).js
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2019).symbols
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es2019).types
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es3).js
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es3).symbols
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es3).types
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es5).js
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es5).symbols
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=es5).types
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=esnext).js
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=esnext).symbols
 create mode 100644 tests/baselines/reference/numericUnderscoredSeparator(target=esnext).types
 create mode 100644 tests/cases/compiler/numericUnderscoredSeparator.ts

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index ebfb7ff3e49a6..94d0fb3933a56 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -4600,7 +4600,8 @@ namespace ts {
 
             const flags = (neverAsciiEscape ? GetLiteralTextFlags.NeverAsciiEscape : 0)
                 | (jsxAttributeEscape ? GetLiteralTextFlags.JsxAttributeEscape : 0)
-                | (printerOptions.terminateUnterminatedLiterals ? GetLiteralTextFlags.TerminateUnterminatedLiterals : 0);
+                | (printerOptions.terminateUnterminatedLiterals ? GetLiteralTextFlags.TerminateUnterminatedLiterals : 0)
+                | (printerOptions.target && printerOptions.target === ScriptTarget.ESNext ? GetLiteralTextFlags.AllowNumericSeparator : 0);
 
             return getLiteralText(node, currentSourceFile!, flags);
         }
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 4d23dcdac294f..e9686b23c1a69 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -616,15 +616,13 @@ namespace ts {
         NeverAsciiEscape = 1 << 0,
         JsxAttributeEscape = 1 << 1,
         TerminateUnterminatedLiterals = 1 << 2,
+        AllowNumericSeparator = 1 << 3
     }
 
     export function getLiteralText(node: LiteralLikeNode, sourceFile: SourceFile, flags: GetLiteralTextFlags) {
         // If we don't need to downlevel and we can reach the original source text using
         // the node's parent reference, then simply get the text as it was originally written.
-        if (!nodeIsSynthesized(node) && node.parent && !(flags & GetLiteralTextFlags.TerminateUnterminatedLiterals && node.isUnterminated) && !(
-            (isNumericLiteral(node) && node.numericLiteralFlags & TokenFlags.ContainsSeparator) ||
-            isBigIntLiteral(node)
-        )) {
+        if (canUseOriginalText(node, flags)) {
             return getSourceTextOfNodeFromSourceFile(sourceFile, node);
         }
 
@@ -677,6 +675,18 @@ namespace ts {
         return Debug.fail(`Literal kind '${node.kind}' not accounted for.`);
     }
 
+    function canUseOriginalText(node: LiteralLikeNode, flags: GetLiteralTextFlags): boolean {
+        if (nodeIsSynthesized(node) || !node.parent || (flags & GetLiteralTextFlags.TerminateUnterminatedLiterals && node.isUnterminated)) {
+            return false;
+        }
+
+        if (isNumericLiteral(node) && node.numericLiteralFlags & TokenFlags.ContainsSeparator) {
+            return !!(flags & GetLiteralTextFlags.AllowNumericSeparator);
+        }
+
+        return !isBigIntLiteral(node);
+    }
+
     export function getTextOfConstantValue(value: string | number) {
         return isString(value) ? '"' + escapeNonAsciiString(value) + '"' : "" + value;
     }
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).js b/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).js
new file mode 100644
index 0000000000000..786e7e245dce4
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).js
@@ -0,0 +1,12 @@
+//// [numericUnderscoredSeparator.ts]
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0
+
+
+//// [numericUnderscoredSeparator.js]
+1000000000000;
+41349;
+41349;
+10531008;
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).symbols b/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).symbols
new file mode 100644
index 0000000000000..d0ffc9942d074
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0xA0_B0_C0
+No type information for this code.
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).types b/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).types
new file mode 100644
index 0000000000000..8526fc01a4cc3
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2015).types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+>1_000_000_000_000 : 1000000000000
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0xA0_B0_C0
+>0xA0_B0_C0 : 10531008
+
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).js b/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).js
new file mode 100644
index 0000000000000..786e7e245dce4
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).js
@@ -0,0 +1,12 @@
+//// [numericUnderscoredSeparator.ts]
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0
+
+
+//// [numericUnderscoredSeparator.js]
+1000000000000;
+41349;
+41349;
+10531008;
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).symbols b/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).symbols
new file mode 100644
index 0000000000000..d0ffc9942d074
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0xA0_B0_C0
+No type information for this code.
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).types b/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).types
new file mode 100644
index 0000000000000..8526fc01a4cc3
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2016).types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+>1_000_000_000_000 : 1000000000000
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0xA0_B0_C0
+>0xA0_B0_C0 : 10531008
+
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).js b/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).js
new file mode 100644
index 0000000000000..786e7e245dce4
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).js
@@ -0,0 +1,12 @@
+//// [numericUnderscoredSeparator.ts]
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0
+
+
+//// [numericUnderscoredSeparator.js]
+1000000000000;
+41349;
+41349;
+10531008;
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).symbols b/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).symbols
new file mode 100644
index 0000000000000..d0ffc9942d074
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0xA0_B0_C0
+No type information for this code.
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).types b/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).types
new file mode 100644
index 0000000000000..8526fc01a4cc3
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2017).types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+>1_000_000_000_000 : 1000000000000
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0xA0_B0_C0
+>0xA0_B0_C0 : 10531008
+
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).js b/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).js
new file mode 100644
index 0000000000000..786e7e245dce4
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).js
@@ -0,0 +1,12 @@
+//// [numericUnderscoredSeparator.ts]
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0
+
+
+//// [numericUnderscoredSeparator.js]
+1000000000000;
+41349;
+41349;
+10531008;
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).symbols b/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).symbols
new file mode 100644
index 0000000000000..d0ffc9942d074
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0xA0_B0_C0
+No type information for this code.
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).types b/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).types
new file mode 100644
index 0000000000000..8526fc01a4cc3
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2018).types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+>1_000_000_000_000 : 1000000000000
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0xA0_B0_C0
+>0xA0_B0_C0 : 10531008
+
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).js b/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).js
new file mode 100644
index 0000000000000..786e7e245dce4
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).js
@@ -0,0 +1,12 @@
+//// [numericUnderscoredSeparator.ts]
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0
+
+
+//// [numericUnderscoredSeparator.js]
+1000000000000;
+41349;
+41349;
+10531008;
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).symbols b/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).symbols
new file mode 100644
index 0000000000000..d0ffc9942d074
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0xA0_B0_C0
+No type information for this code.
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).types b/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).types
new file mode 100644
index 0000000000000..8526fc01a4cc3
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es2019).types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+>1_000_000_000_000 : 1000000000000
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0xA0_B0_C0
+>0xA0_B0_C0 : 10531008
+
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es3).js b/tests/baselines/reference/numericUnderscoredSeparator(target=es3).js
new file mode 100644
index 0000000000000..786e7e245dce4
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es3).js
@@ -0,0 +1,12 @@
+//// [numericUnderscoredSeparator.ts]
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0
+
+
+//// [numericUnderscoredSeparator.js]
+1000000000000;
+41349;
+41349;
+10531008;
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es3).symbols b/tests/baselines/reference/numericUnderscoredSeparator(target=es3).symbols
new file mode 100644
index 0000000000000..d0ffc9942d074
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es3).symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0xA0_B0_C0
+No type information for this code.
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es3).types b/tests/baselines/reference/numericUnderscoredSeparator(target=es3).types
new file mode 100644
index 0000000000000..8526fc01a4cc3
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es3).types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+>1_000_000_000_000 : 1000000000000
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0xA0_B0_C0
+>0xA0_B0_C0 : 10531008
+
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es5).js b/tests/baselines/reference/numericUnderscoredSeparator(target=es5).js
new file mode 100644
index 0000000000000..786e7e245dce4
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es5).js
@@ -0,0 +1,12 @@
+//// [numericUnderscoredSeparator.ts]
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0
+
+
+//// [numericUnderscoredSeparator.js]
+1000000000000;
+41349;
+41349;
+10531008;
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es5).symbols b/tests/baselines/reference/numericUnderscoredSeparator(target=es5).symbols
new file mode 100644
index 0000000000000..d0ffc9942d074
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es5).symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0xA0_B0_C0
+No type information for this code.
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=es5).types b/tests/baselines/reference/numericUnderscoredSeparator(target=es5).types
new file mode 100644
index 0000000000000..8526fc01a4cc3
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=es5).types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+>1_000_000_000_000 : 1000000000000
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0xA0_B0_C0
+>0xA0_B0_C0 : 10531008
+
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).js b/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).js
new file mode 100644
index 0000000000000..6d0e5b102c5ea
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).js
@@ -0,0 +1,12 @@
+//// [numericUnderscoredSeparator.ts]
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0
+
+
+//// [numericUnderscoredSeparator.js]
+1_000_000_000_000;
+0b1010_0001_1000_0101;
+0b1010_0001_1000_0101;
+0xA0_B0_C0;
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).symbols b/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).symbols
new file mode 100644
index 0000000000000..d0ffc9942d074
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0b1010_0001_1000_0101
+No type information for this code.0xA0_B0_C0
+No type information for this code.
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).types b/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).types
new file mode 100644
index 0000000000000..8526fc01a4cc3
--- /dev/null
+++ b/tests/baselines/reference/numericUnderscoredSeparator(target=esnext).types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/numericUnderscoredSeparator.ts ===
+1_000_000_000_000
+>1_000_000_000_000 : 1000000000000
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0b1010_0001_1000_0101
+>0b1010_0001_1000_0101 : 41349
+
+0xA0_B0_C0
+>0xA0_B0_C0 : 10531008
+
diff --git a/tests/cases/compiler/numericUnderscoredSeparator.ts b/tests/cases/compiler/numericUnderscoredSeparator.ts
new file mode 100644
index 0000000000000..3b532de43880a
--- /dev/null
+++ b/tests/cases/compiler/numericUnderscoredSeparator.ts
@@ -0,0 +1,6 @@
+// @target: es3,es5,es2015,es2016,es2017,es2018,es2019,esnext
+
+1_000_000_000_000
+0b1010_0001_1000_0101
+0b1010_0001_1000_0101
+0xA0_B0_C0