Merge pull request #28896 from JoshuaKGoldberg/n-identifier-after-numeric-literal-error

Better error message for invalid bigint literals ending with n
2026-05-15 12:51:30 -05:00 · 2018-12-18 11:38:06 -08:00
parent 4f7184a587 0d7e3f82d4
commit 3edd2d6893
9 changed files with 58 additions and 43 deletions
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1015,6 +1015,14 @@
        "category": "Error",
        "code": 1351
    },
+    "A bigint literal cannot use exponential notation.": {
+        "category": "Error",
+        "code": 1352
+    },
+    "A bigint literal must be an integer.": {
+        "category": "Error",
+        "code": 1353
+    },

    "Duplicate identifier '{0}'.": {
        "category": "Error",
--- a/src/compiler/scanner.ts
+++ b/src/compiler/scanner.ts
@@ -976,7 +976,7 @@ namespace ts {
            }

            if (decimalFragment !== undefined || tokenFlags & TokenFlags.Scientific) {
-                checkForIdentifierStartAfterNumericLiteral();
+                checkForIdentifierStartAfterNumericLiteral(start, decimalFragment === undefined && !!(tokenFlags & TokenFlags.Scientific));
                return {
                    type: SyntaxKind.NumericLiteral,
                    value: "" + +result // if value is not an integer, it can be safely coerced to a number
@@ -985,20 +985,31 @@ namespace ts {
            else {
                tokenValue = result;
                const type = checkBigIntSuffix(); // if value is an integer, check whether it is a bigint
-                checkForIdentifierStartAfterNumericLiteral();
+                checkForIdentifierStartAfterNumericLiteral(start);
                return { type, value: tokenValue };
            }
        }

-        function checkForIdentifierStartAfterNumericLiteral() {
+        function checkForIdentifierStartAfterNumericLiteral(numericStart: number, isScientific?: boolean) {
            if (!isIdentifierStart(text.charCodeAt(pos), languageVersion)) {
                return;
            }

            const identifierStart = pos;
            const { length } = scanIdentifierParts();
-            error(Diagnostics.An_identifier_or_keyword_cannot_immediately_follow_a_numeric_literal, identifierStart, length);
-            pos = identifierStart;
+
+            if (length === 1 && text[identifierStart] === "n") {
+                if (isScientific) {
+                    error(Diagnostics.A_bigint_literal_cannot_use_exponential_notation, numericStart, identifierStart - numericStart + 1);
+                }
+                else {
+                    error(Diagnostics.A_bigint_literal_must_be_an_integer, numericStart, identifierStart - numericStart + 1);
+                }
+            }
+            else {
+                error(Diagnostics.An_identifier_or_keyword_cannot_immediately_follow_a_numeric_literal, identifierStart, length);
+                pos = identifierStart;
+            }
        }

        function scanOctalDigits(): number {
--- a/tests/baselines/reference/identifierStartAfterNumericLiteral.errors.txt
+++ b/tests/baselines/reference/identifierStartAfterNumericLiteral.errors.txt
@@ -9,10 +9,12 @@ tests/cases/compiler/identifierStartAfterNumericLiteral.ts(6,5): error TS1124: D
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(6,6): error TS2538: Type 'null' cannot be used as an index type.
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(7,2): error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(8,4): error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
+tests/cases/compiler/identifierStartAfterNumericLiteral.ts(9,1): error TS1352: A bigint literal cannot use exponential notation.
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(9,3): error TS1124: Digit expected.
-tests/cases/compiler/identifierStartAfterNumericLiteral.ts(9,3): error TS2304: Cannot find name 'n'.
+tests/cases/compiler/identifierStartAfterNumericLiteral.ts(9,5): error TS2538: Type 'null' cannot be used as an index type.
+tests/cases/compiler/identifierStartAfterNumericLiteral.ts(10,1): error TS1352: A bigint literal cannot use exponential notation.
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(10,5): error TS1124: Digit expected.
-tests/cases/compiler/identifierStartAfterNumericLiteral.ts(10,5): error TS2304: Cannot find name 'n'.
+tests/cases/compiler/identifierStartAfterNumericLiteral.ts(10,7): error TS2538: Type 'null' cannot be used as an index type.
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(11,2): error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(11,2): error TS2304: Cannot find name 'a'.
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(12,4): error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
@@ -35,7 +37,7 @@ tests/cases/compiler/identifierStartAfterNumericLiteral.ts(26,5): error TS1351:
 tests/cases/compiler/identifierStartAfterNumericLiteral.ts(26,5): error TS2304: Cannot find name 'abc'.


-==== tests/cases/compiler/identifierStartAfterNumericLiteral.ts (35 errors) ====
+==== tests/cases/compiler/identifierStartAfterNumericLiteral.ts (37 errors) ====
    let valueIn = 3in[null];
                   ~~
 !!! error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
@@ -67,15 +69,19 @@ tests/cases/compiler/identifierStartAfterNumericLiteral.ts(26,5): error TS2304:
       ~~
 !!! error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
    3en[null]
+    ~~~
+!!! error TS1352: A bigint literal cannot use exponential notation.
      
 !!! error TS1124: Digit expected.
-      ~
-!!! error TS2304: Cannot find name 'n'.
+        ~~~~
+!!! error TS2538: Type 'null' cannot be used as an index type.
    123en[null]
+    ~~~~~
+!!! error TS1352: A bigint literal cannot use exponential notation.
        
 !!! error TS1124: Digit expected.
-        ~
-!!! error TS2304: Cannot find name 'n'.
+          ~~~~
+!!! error TS2538: Type 'null' cannot be used as an index type.
    1a
     ~
 !!! error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
--- a/tests/baselines/reference/identifierStartAfterNumericLiteral.js
+++ b/tests/baselines/reference/identifierStartAfterNumericLiteral.js
@@ -37,10 +37,8 @@ a[null];
 123e[null];
 3 in [null];
 123 in [null];
-3e;
-n[null];
-123e;
-n[null];
+3en[null];
+123en[null];
 1;
 a;
 123;
--- a/tests/baselines/reference/identifierStartAfterNumericLiteral.types
+++ b/tests/baselines/reference/identifierStartAfterNumericLiteral.types
@@ -41,15 +41,13 @@ let valueIn = 3in[null];
 >null : null

 3en[null]
->3e : 3
->n[null] : any
->n : any
+>3en[null] : any
+>3en : 3
 >null : null

 123en[null]
->123e : 123
->n[null] : any
->n : any
+>123en[null] : any
+>123en : 123
 >null : null

 1a
--- a/tests/baselines/reference/parseBigInt.errors.txt
+++ b/tests/baselines/reference/parseBigInt.errors.txt
@@ -1,9 +1,9 @@
 tests/cases/compiler/parseBigInt.ts(51,20): error TS2736: Operator '+' cannot be applied to type '123n'.
 tests/cases/compiler/parseBigInt.ts(52,23): error TS2736: Operator '+' cannot be applied to type '291n'.
 tests/cases/compiler/parseBigInt.ts(56,25): error TS1005: ',' expected.
-tests/cases/compiler/parseBigInt.ts(57,25): error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
-tests/cases/compiler/parseBigInt.ts(58,22): error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
-tests/cases/compiler/parseBigInt.ts(59,28): error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
+tests/cases/compiler/parseBigInt.ts(57,22): error TS1352: A bigint literal cannot use exponential notation.
+tests/cases/compiler/parseBigInt.ts(58,19): error TS1353: A bigint literal must be an integer.
+tests/cases/compiler/parseBigInt.ts(59,26): error TS1353: A bigint literal must be an integer.
 tests/cases/compiler/parseBigInt.ts(60,23): error TS1177: Binary digit expected.
 tests/cases/compiler/parseBigInt.ts(61,20): error TS1178: Octal digit expected.
 tests/cases/compiler/parseBigInt.ts(62,20): error TS1125: Hexadecimal digit expected.
@@ -81,14 +81,14 @@ tests/cases/compiler/parseBigInt.ts(70,72): error TS2345: Argument of type '3' i
                            ~
 !!! error TS1005: ',' expected.
    { const scientific = 1e2n; }
-                            ~
-!!! error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
+                         ~~~~
+!!! error TS1352: A bigint literal cannot use exponential notation.
    { const decimal = 4.1n; }
-                         ~
-!!! error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
+                      ~~~~
+!!! error TS1353: A bigint literal must be an integer.
    { const leadingDecimal = .1n; }
-                               ~
-!!! error TS1351: An identifier or keyword cannot immediately follow a numeric literal.
+                             ~~~
+!!! error TS1353: A bigint literal must be an integer.
    const emptyBinary = 0bn; // should error but infer 0n
                          
 !!! error TS1177: Binary digit expected.
--- a/tests/baselines/reference/parseBigInt.js
+++ b/tests/baselines/reference/parseBigInt.js
@@ -123,13 +123,13 @@ const unaryPlusHex = +0x123n;
    const legacyOct = 0123, n;
 }
 {
-    const scientific = 1e2, n;
+    const scientific = 1e2n;
 }
 {
-    const decimal = 4.1, n;
+    const decimal = 4.1n;
 }
 {
-    const leadingDecimal = .1, n;
+    const leadingDecimal = .1n;
 }
 const emptyBinary = 0n; // should error but infer 0n
 const emptyOct = 0n; // should error but infer 0n
--- a/tests/baselines/reference/parseBigInt.symbols
+++ b/tests/baselines/reference/parseBigInt.symbols
@@ -131,15 +131,12 @@ const unaryPlusHex = +0x123n;

 { const scientific = 1e2n; }
 >scientific : Symbol(scientific, Decl(parseBigInt.ts, 56, 7))
->n : Symbol(n, Decl(parseBigInt.ts, 56, 24))

 { const decimal = 4.1n; }
 >decimal : Symbol(decimal, Decl(parseBigInt.ts, 57, 7))
->n : Symbol(n, Decl(parseBigInt.ts, 57, 21))

 { const leadingDecimal = .1n; }
 >leadingDecimal : Symbol(leadingDecimal, Decl(parseBigInt.ts, 58, 7))
->n : Symbol(n, Decl(parseBigInt.ts, 58, 27))

 const emptyBinary = 0bn; // should error but infer 0n
 >emptyBinary : Symbol(emptyBinary, Decl(parseBigInt.ts, 59, 5))
--- a/tests/baselines/reference/parseBigInt.types
+++ b/tests/baselines/reference/parseBigInt.types
@@ -180,18 +180,15 @@ const unaryPlusHex = +0x123n;

 { const scientific = 1e2n; }
 >scientific : 100
->1e2 : 100
->n : any
+>1e2n : 100

 { const decimal = 4.1n; }
 >decimal : 4.1
->4.1 : 4.1
->n : any
+>4.1n : 4.1

 { const leadingDecimal = .1n; }
 >leadingDecimal : 0.1
->.1 : 0.1
->n : any
+>.1n : 0.1

 const emptyBinary = 0bn; // should error but infer 0n
 >emptyBinary : 0n