disallow nan and infinity in enum member

src/compiler/checker.ts

@@ -24376,7 +24376,11 @@ namespace ts {
                     case SyntaxKind.ParenthesizedExpression:
                         return evaluate((<ParenthesizedExpression>expr).expression);
                     case SyntaxKind.Identifier:
-                        return nodeIsMissing(expr) ? 0 : evaluateEnumMember(expr, getSymbolOfNode(member.parent), (<Identifier>expr).escapedText);
+                        const identifier = <Identifier>expr;
+                        if (isInfinityOrNaNString(identifier.escapedText)) {
+                            return +(identifier.escapedText);
+                        }
+                        return nodeIsMissing(expr) ? 0 : evaluateEnumMember(expr, getSymbolOfNode(member.parent), identifier.escapedText);
                     case SyntaxKind.ElementAccessExpression:
                     case SyntaxKind.PropertyAccessExpression:
                         const ex = <PropertyAccessExpression | ElementAccessExpression>expr;

tests/baselines/reference/enumConstantMembers.errors.txt

@@ -0,0 +1,64 @@
+tests/cases/conformance/enums/enumConstantMembers.ts(32,9): error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+tests/cases/conformance/enums/enumConstantMembers.ts(33,9): error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+tests/cases/conformance/enums/enumConstantMembers.ts(34,9): error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+tests/cases/conformance/enums/enumConstantMembers.ts(35,9): error TS2478: 'const' enum member initializer was evaluated to disallowed value 'NaN'.
+tests/cases/conformance/enums/enumConstantMembers.ts(36,9): error TS2478: 'const' enum member initializer was evaluated to disallowed value 'NaN'.
+tests/cases/conformance/enums/enumConstantMembers.ts(37,9): error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+tests/cases/conformance/enums/enumConstantMembers.ts(38,9): error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+
+
+==== tests/cases/conformance/enums/enumConstantMembers.ts (7 errors) ====
+    // Constant members allow negatives, but not decimals. Also hex literals are allowed
+    enum E1 {
+        a = 1,
+        b
+    }
+    enum E2 {
+        a = - 1,
+        b
+    }
+    enum E3 {
+        a = 0.1,
+        b // Error because 0.1 is not a constant
+    }
+
+    declare enum E4 {
+        a = 1,
+        b = -1,
+        c = 0.1 // Not a constant
+    }
+
+    enum E5 {
+        a = 1 / 0,
+        b = 2 / 0.0,
+        c = 1.0 / 0.0,
+        d = 0.0 / 0.0,
+        e = NaN,
+        f = Infinity,
+        g = -Infinity
+    }
+
+    const enum E6 {
+        a = 1 / 0,
+            ~~~~~
+!!! error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+        b = 2 / 0.0,
+            ~~~~~~~
+!!! error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+        c = 1.0 / 0.0,
+            ~~~~~~~~~
+!!! error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+        d = 0.0 / 0.0,
+            ~~~~~~~~~
+!!! error TS2478: 'const' enum member initializer was evaluated to disallowed value 'NaN'.
+        e = NaN,
+            ~~~
+!!! error TS2478: 'const' enum member initializer was evaluated to disallowed value 'NaN'.
+        f = Infinity,
+            ~~~~~~~~
+!!! error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+        g = -Infinity
+            ~~~~~~~~~
+!!! error TS2477: 'const' enum member initializer was evaluated to a non-finite value.
+    }
+

tests/baselines/reference/enumConstantMembers.js

@@ -17,7 +17,28 @@ declare enum E4 {
     a = 1,
     b = -1,
     c = 0.1 // Not a constant
-}
+}
+
+enum E5 {
+    a = 1 / 0,
+    b = 2 / 0.0,
+    c = 1.0 / 0.0,
+    d = 0.0 / 0.0,
+    e = NaN,
+    f = Infinity,
+    g = -Infinity
+}
+
+const enum E6 {
+    a = 1 / 0,
+    b = 2 / 0.0,
+    c = 1.0 / 0.0,
+    d = 0.0 / 0.0,
+    e = NaN,
+    f = Infinity,
+    g = -Infinity
+}
+
 
 //// [enumConstantMembers.js]
 // Constant members allow negatives, but not decimals. Also hex literals are allowed
@@ -36,3 +57,13 @@ var E3;
     E3[E3["a"] = 0.1] = "a";
     E3[E3["b"] = 1.1] = "b"; // Error because 0.1 is not a constant
 })(E3 || (E3 = {}));
+var E5;
+(function (E5) {
+    E5[E5["a"] = Infinity] = "a";
+    E5[E5["b"] = Infinity] = "b";
+    E5[E5["c"] = Infinity] = "c";
+    E5[E5["d"] = NaN] = "d";
+    E5[E5["e"] = NaN] = "e";
+    E5[E5["f"] = Infinity] = "f";
+    E5[E5["g"] = -Infinity] = "g";
+})(E5 || (E5 = {}));

tests/baselines/reference/enumConstantMembers.symbols

@@ -40,3 +40,60 @@ declare enum E4 {
     c = 0.1 // Not a constant
 >c : Symbol(E4.c, Decl(enumConstantMembers.ts, 16, 11))
 }
+
+enum E5 {
+>E5 : Symbol(E5, Decl(enumConstantMembers.ts, 18, 1))
+
+    a = 1 / 0,
+>a : Symbol(E5.a, Decl(enumConstantMembers.ts, 20, 9))
+
+    b = 2 / 0.0,
+>b : Symbol(E5.b, Decl(enumConstantMembers.ts, 21, 14))
+
+    c = 1.0 / 0.0,
+>c : Symbol(E5.c, Decl(enumConstantMembers.ts, 22, 16))
+
+    d = 0.0 / 0.0,
+>d : Symbol(E5.d, Decl(enumConstantMembers.ts, 23, 18))
+
+    e = NaN,
+>e : Symbol(E5.e, Decl(enumConstantMembers.ts, 24, 18))
+>NaN : Symbol(NaN, Decl(lib.d.ts, --, --))
+
+    f = Infinity,
+>f : Symbol(E5.f, Decl(enumConstantMembers.ts, 25, 12))
+>Infinity : Symbol(Infinity, Decl(lib.d.ts, --, --))
+
+    g = -Infinity
+>g : Symbol(E5.g, Decl(enumConstantMembers.ts, 26, 17))
+>Infinity : Symbol(Infinity, Decl(lib.d.ts, --, --))
+}
+
+const enum E6 {
+>E6 : Symbol(E6, Decl(enumConstantMembers.ts, 28, 1))
+
+    a = 1 / 0,
+>a : Symbol(E6.a, Decl(enumConstantMembers.ts, 30, 15))
+
+    b = 2 / 0.0,
+>b : Symbol(E6.b, Decl(enumConstantMembers.ts, 31, 14))
+
+    c = 1.0 / 0.0,
+>c : Symbol(E6.c, Decl(enumConstantMembers.ts, 32, 16))
+
+    d = 0.0 / 0.0,
+>d : Symbol(E6.d, Decl(enumConstantMembers.ts, 33, 18))
+
+    e = NaN,
+>e : Symbol(E6.e, Decl(enumConstantMembers.ts, 34, 18))
+>NaN : Symbol(NaN, Decl(lib.d.ts, --, --))
+
+    f = Infinity,
+>f : Symbol(E6.f, Decl(enumConstantMembers.ts, 35, 12))
+>Infinity : Symbol(Infinity, Decl(lib.d.ts, --, --))
+
+    g = -Infinity
+>g : Symbol(E6.g, Decl(enumConstantMembers.ts, 36, 17))
+>Infinity : Symbol(Infinity, Decl(lib.d.ts, --, --))
+}
+

tests/baselines/reference/enumConstantMembers.types

@@ -48,3 +48,86 @@ declare enum E4 {
 >c : E4.c
 >0.1 : 0.1
 }
+
+enum E5 {
+>E5 : E5
+
+    a = 1 / 0,
+>a : E5
+>1 / 0 : number
+>1 : 1
+>0 : 0
+
+    b = 2 / 0.0,
+>b : E5
+>2 / 0.0 : number
+>2 : 2
+>0.0 : 0
+
+    c = 1.0 / 0.0,
+>c : E5
+>1.0 / 0.0 : number
+>1.0 : 1
+>0.0 : 0
+
+    d = 0.0 / 0.0,
+>d : E5
+>0.0 / 0.0 : number
+>0.0 : 0
+>0.0 : 0
+
+    e = NaN,
+>e : E5
+>NaN : number
+
+    f = Infinity,
+>f : E5
+>Infinity : number
+
+    g = -Infinity
+>g : E5
+>-Infinity : number
+>Infinity : number
+}
+
+const enum E6 {
+>E6 : E6
+
+    a = 1 / 0,
+>a : E6
+>1 / 0 : number
+>1 : 1
+>0 : 0
+
+    b = 2 / 0.0,
+>b : E6
+>2 / 0.0 : number
+>2 : 2
+>0.0 : 0
+
+    c = 1.0 / 0.0,
+>c : E6
+>1.0 / 0.0 : number
+>1.0 : 1
+>0.0 : 0
+
+    d = 0.0 / 0.0,
+>d : E6
+>0.0 / 0.0 : number
+>0.0 : 0
+>0.0 : 0
+
+    e = NaN,
+>e : E6
+>NaN : number
+
+    f = Infinity,
+>f : E6
+>Infinity : number
+
+    g = -Infinity
+>g : E6
+>-Infinity : number
+>Infinity : number
+}
+

tests/cases/conformance/enums/enumConstantMembers.ts

@@ -16,4 +16,24 @@ declare enum E4 {
     a = 1,
     b = -1,
     c = 0.1 // Not a constant
-}
+}
+
+enum E5 {
+    a = 1 / 0,
+    b = 2 / 0.0,
+    c = 1.0 / 0.0,
+    d = 0.0 / 0.0,
+    e = NaN,
+    f = Infinity,
+    g = -Infinity
+}
+
+const enum E6 {
+    a = 1 / 0,
+    b = 2 / 0.0,
+    c = 1.0 / 0.0,
+    d = 0.0 / 0.0,
+    e = NaN,
+    f = Infinity,
+    g = -Infinity
+}