Limit the narrow-to-fresh rule added with boolean literals to only boolean literals (#27274)
* Remove the narrow-to-fresh rule added with boolean literals
* Revert "Remove the narrow-to-fresh rule added with boolean literals"
This reverts commit 9f96fe5da3.
* Only apply freshness to booleans for now
* Add largeish example from issue
* Should be AND not OR
* Add minor improvements suggested by @ahejelsberg
* Reorder conditional a bit
This commit is contained in:
Wesley Wigham
GitHub
parent
b7fc092404
commit
e1c8dc2768
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@ -8873,7 +8873,7 @@ namespace ts {
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}
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switch (unionReduction) {
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case UnionReduction.Literal:
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if (includes & TypeFlags.StringOrNumberLiteralOrUnique) {
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if (includes & TypeFlags.StringOrNumberLiteralOrUnique | TypeFlags.BooleanLiteral) {
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removeRedundantLiteralTypes(typeSet, includes);
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}
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break;
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@ -12938,8 +12938,8 @@ namespace ts {
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function getDefinitelyFalsyPartOfType(type: Type): Type {
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return type.flags & TypeFlags.String ? emptyStringType :
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type.flags & TypeFlags.Number ? zeroType :
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type.flags & TypeFlags.Boolean || type === regularFalseType ? regularFalseType :
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type === falseType ? falseType :
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type === regularFalseType ||
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type === falseType ||
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type.flags & (TypeFlags.Void | TypeFlags.Undefined | TypeFlags.Null) ||
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type.flags & TypeFlags.StringLiteral && (<LiteralType>type).value === "" ||
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type.flags & TypeFlags.NumberLiteral && (<LiteralType>type).value === 0 ? type :
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@ -14214,7 +14214,7 @@ namespace ts {
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return assignedType;
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}
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let reducedType = filterType(declaredType, t => typeMaybeAssignableTo(assignedType, t));
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if (assignedType.flags & (TypeFlags.FreshLiteral | TypeFlags.Literal)) {
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if (assignedType.flags & TypeFlags.FreshLiteral && assignedType.flags & TypeFlags.BooleanLiteral) {
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reducedType = mapType(reducedType, getFreshTypeOfLiteralType); // Ensure that if the assignment is a fresh type, that we narrow to fresh types
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}
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// Our crude heuristic produces an invalid result in some cases: see GH#26130.
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@ -0,0 +1,72 @@
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tests/cases/compiler/literalFreshnessPropagationOnNarrowing.ts(37,5): error TS2322: Type '"y"' is not assignable to type '"x"'.
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tests/cases/compiler/literalFreshnessPropagationOnNarrowing.ts(60,5): error TS2322: Type 'string[]' is not assignable to type 'XY[]'.
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Type 'string' is not assignable to type 'XY'.
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==== tests/cases/compiler/literalFreshnessPropagationOnNarrowing.ts (2 errors) ====
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function f1() {
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let b = true;
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let obj = { b };
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// Desired: OK
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// 3.0: OK
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// 3.1 as-is: OK
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// 3.1 minus widening propagation: error
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obj.b = false;
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}
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function f2() {
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type Element = (string | false);
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type ElementOrArray = Element | Element[];
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let el: Element = null as any;
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let arr: Element[] = null as any;
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let elOrA: ElementOrArray = null as any;
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// Desired/actual: All OK
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let a1: ElementOrArray = el;
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let a2: ElementOrArray = arr;
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let a3: ElementOrArray = [el];
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let a4: ElementOrArray = Array.isArray(elOrA) ? elOrA : [elOrA];
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// Desired: OK
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// 3.0: Error
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// 3.1: OK
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let a5: ElementOrArray = [...Array.isArray(elOrA) ? elOrA : [elOrA]];
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}
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function f3() {
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type XY = 'x' | 'y';
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const x: XY = 'x';
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let x2 = x;
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// Desired: OK (up for debate?)
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// 3.0: Error
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// 3.1 as-is: OK
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x2 = 'y';
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~~
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!!! error TS2322: Type '"y"' is not assignable to type '"x"'.
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// Desired/actual: All OK
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let x3: XY = x;
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x3 = 'y';
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}
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function f4() {
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const x: boolean = true;
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let x1 = x;
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// Desired: OK
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// 3.0: OK
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// 3.1: OK
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// 3.1 minus widening propagation: error
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x1 = false;
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}
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function f5() {
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type XY = 'x' | 'y';
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let arr: XY[] = ['x'];
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arr = ['y'];
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// Desired: OK
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// Error in all extant branches
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arr = [...['y']];
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~~~
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!!! error TS2322: Type 'string[]' is not assignable to type 'XY[]'.
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!!! error TS2322: Type 'string' is not assignable to type 'XY'.
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}
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@ -0,0 +1,114 @@
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//// [literalFreshnessPropagationOnNarrowing.ts]
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function f1() {
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let b = true;
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let obj = { b };
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// Desired: OK
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// 3.0: OK
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// 3.1 as-is: OK
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// 3.1 minus widening propagation: error
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obj.b = false;
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}
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function f2() {
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type Element = (string | false);
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type ElementOrArray = Element | Element[];
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let el: Element = null as any;
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let arr: Element[] = null as any;
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let elOrA: ElementOrArray = null as any;
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// Desired/actual: All OK
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let a1: ElementOrArray = el;
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let a2: ElementOrArray = arr;
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let a3: ElementOrArray = [el];
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let a4: ElementOrArray = Array.isArray(elOrA) ? elOrA : [elOrA];
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// Desired: OK
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// 3.0: Error
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// 3.1: OK
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let a5: ElementOrArray = [...Array.isArray(elOrA) ? elOrA : [elOrA]];
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}
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function f3() {
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type XY = 'x' | 'y';
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const x: XY = 'x';
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let x2 = x;
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// Desired: OK (up for debate?)
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// 3.0: Error
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// 3.1 as-is: OK
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x2 = 'y';
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// Desired/actual: All OK
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let x3: XY = x;
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x3 = 'y';
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}
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function f4() {
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const x: boolean = true;
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let x1 = x;
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// Desired: OK
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// 3.0: OK
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// 3.1: OK
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// 3.1 minus widening propagation: error
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x1 = false;
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}
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function f5() {
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type XY = 'x' | 'y';
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let arr: XY[] = ['x'];
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arr = ['y'];
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// Desired: OK
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// Error in all extant branches
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arr = [...['y']];
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}
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//// [literalFreshnessPropagationOnNarrowing.js]
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function f1() {
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var b = true;
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var obj = { b: b };
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// Desired: OK
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// 3.0: OK
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// 3.1 as-is: OK
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// 3.1 minus widening propagation: error
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obj.b = false;
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}
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function f2() {
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var el = null;
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var arr = null;
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var elOrA = null;
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// Desired/actual: All OK
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var a1 = el;
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var a2 = arr;
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var a3 = [el];
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var a4 = Array.isArray(elOrA) ? elOrA : [elOrA];
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// Desired: OK
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// 3.0: Error
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// 3.1: OK
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var a5 = (Array.isArray(elOrA) ? elOrA : [elOrA]).slice();
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}
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function f3() {
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var x = 'x';
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var x2 = x;
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// Desired: OK (up for debate?)
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// 3.0: Error
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// 3.1 as-is: OK
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x2 = 'y';
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// Desired/actual: All OK
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var x3 = x;
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x3 = 'y';
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}
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function f4() {
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var x = true;
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var x1 = x;
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// Desired: OK
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// 3.0: OK
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// 3.1: OK
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// 3.1 minus widening propagation: error
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x1 = false;
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}
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function f5() {
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var arr = ['x'];
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arr = ['y'];
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// Desired: OK
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// Error in all extant branches
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arr = ['y'];
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}
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@ -0,0 +1,150 @@
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=== tests/cases/compiler/literalFreshnessPropagationOnNarrowing.ts ===
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function f1() {
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>f1 : Symbol(f1, Decl(literalFreshnessPropagationOnNarrowing.ts, 0, 0))
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let b = true;
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>b : Symbol(b, Decl(literalFreshnessPropagationOnNarrowing.ts, 1, 7))
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let obj = { b };
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>obj : Symbol(obj, Decl(literalFreshnessPropagationOnNarrowing.ts, 2, 7))
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>b : Symbol(b, Decl(literalFreshnessPropagationOnNarrowing.ts, 2, 15))
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// Desired: OK
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// 3.0: OK
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// 3.1 as-is: OK
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// 3.1 minus widening propagation: error
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obj.b = false;
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>obj.b : Symbol(b, Decl(literalFreshnessPropagationOnNarrowing.ts, 2, 15))
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>obj : Symbol(obj, Decl(literalFreshnessPropagationOnNarrowing.ts, 2, 7))
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>b : Symbol(b, Decl(literalFreshnessPropagationOnNarrowing.ts, 2, 15))
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}
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function f2() {
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>f2 : Symbol(f2, Decl(literalFreshnessPropagationOnNarrowing.ts, 8, 1))
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type Element = (string | false);
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>Element : Symbol(Element, Decl(literalFreshnessPropagationOnNarrowing.ts, 10, 15))
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type ElementOrArray = Element | Element[];
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>ElementOrArray : Symbol(ElementOrArray, Decl(literalFreshnessPropagationOnNarrowing.ts, 11, 36))
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>Element : Symbol(Element, Decl(literalFreshnessPropagationOnNarrowing.ts, 10, 15))
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>Element : Symbol(Element, Decl(literalFreshnessPropagationOnNarrowing.ts, 10, 15))
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let el: Element = null as any;
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>el : Symbol(el, Decl(literalFreshnessPropagationOnNarrowing.ts, 13, 7))
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>Element : Symbol(Element, Decl(literalFreshnessPropagationOnNarrowing.ts, 10, 15))
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let arr: Element[] = null as any;
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>arr : Symbol(arr, Decl(literalFreshnessPropagationOnNarrowing.ts, 14, 7))
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>Element : Symbol(Element, Decl(literalFreshnessPropagationOnNarrowing.ts, 10, 15))
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let elOrA: ElementOrArray = null as any;
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>elOrA : Symbol(elOrA, Decl(literalFreshnessPropagationOnNarrowing.ts, 15, 7))
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>ElementOrArray : Symbol(ElementOrArray, Decl(literalFreshnessPropagationOnNarrowing.ts, 11, 36))
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// Desired/actual: All OK
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let a1: ElementOrArray = el;
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>a1 : Symbol(a1, Decl(literalFreshnessPropagationOnNarrowing.ts, 18, 7))
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>ElementOrArray : Symbol(ElementOrArray, Decl(literalFreshnessPropagationOnNarrowing.ts, 11, 36))
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>el : Symbol(el, Decl(literalFreshnessPropagationOnNarrowing.ts, 13, 7))
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let a2: ElementOrArray = arr;
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>a2 : Symbol(a2, Decl(literalFreshnessPropagationOnNarrowing.ts, 19, 7))
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>ElementOrArray : Symbol(ElementOrArray, Decl(literalFreshnessPropagationOnNarrowing.ts, 11, 36))
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>arr : Symbol(arr, Decl(literalFreshnessPropagationOnNarrowing.ts, 14, 7))
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let a3: ElementOrArray = [el];
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>a3 : Symbol(a3, Decl(literalFreshnessPropagationOnNarrowing.ts, 20, 7))
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>ElementOrArray : Symbol(ElementOrArray, Decl(literalFreshnessPropagationOnNarrowing.ts, 11, 36))
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>el : Symbol(el, Decl(literalFreshnessPropagationOnNarrowing.ts, 13, 7))
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let a4: ElementOrArray = Array.isArray(elOrA) ? elOrA : [elOrA];
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>a4 : Symbol(a4, Decl(literalFreshnessPropagationOnNarrowing.ts, 21, 7))
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>ElementOrArray : Symbol(ElementOrArray, Decl(literalFreshnessPropagationOnNarrowing.ts, 11, 36))
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>Array.isArray : Symbol(ArrayConstructor.isArray, Decl(lib.es5.d.ts, --, --))
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>Array : Symbol(Array, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
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>isArray : Symbol(ArrayConstructor.isArray, Decl(lib.es5.d.ts, --, --))
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>elOrA : Symbol(elOrA, Decl(literalFreshnessPropagationOnNarrowing.ts, 15, 7))
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>elOrA : Symbol(elOrA, Decl(literalFreshnessPropagationOnNarrowing.ts, 15, 7))
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>elOrA : Symbol(elOrA, Decl(literalFreshnessPropagationOnNarrowing.ts, 15, 7))
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// Desired: OK
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// 3.0: Error
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// 3.1: OK
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let a5: ElementOrArray = [...Array.isArray(elOrA) ? elOrA : [elOrA]];
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>a5 : Symbol(a5, Decl(literalFreshnessPropagationOnNarrowing.ts, 26, 7))
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>ElementOrArray : Symbol(ElementOrArray, Decl(literalFreshnessPropagationOnNarrowing.ts, 11, 36))
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>Array.isArray : Symbol(ArrayConstructor.isArray, Decl(lib.es5.d.ts, --, --))
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>Array : Symbol(Array, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
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>isArray : Symbol(ArrayConstructor.isArray, Decl(lib.es5.d.ts, --, --))
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>elOrA : Symbol(elOrA, Decl(literalFreshnessPropagationOnNarrowing.ts, 15, 7))
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>elOrA : Symbol(elOrA, Decl(literalFreshnessPropagationOnNarrowing.ts, 15, 7))
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>elOrA : Symbol(elOrA, Decl(literalFreshnessPropagationOnNarrowing.ts, 15, 7))
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}
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function f3() {
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>f3 : Symbol(f3, Decl(literalFreshnessPropagationOnNarrowing.ts, 27, 1))
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type XY = 'x' | 'y';
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>XY : Symbol(XY, Decl(literalFreshnessPropagationOnNarrowing.ts, 29, 15))
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const x: XY = 'x';
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>x : Symbol(x, Decl(literalFreshnessPropagationOnNarrowing.ts, 31, 9))
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>XY : Symbol(XY, Decl(literalFreshnessPropagationOnNarrowing.ts, 29, 15))
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let x2 = x;
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>x2 : Symbol(x2, Decl(literalFreshnessPropagationOnNarrowing.ts, 32, 7))
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>x : Symbol(x, Decl(literalFreshnessPropagationOnNarrowing.ts, 31, 9))
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// Desired: OK (up for debate?)
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// 3.0: Error
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// 3.1 as-is: OK
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x2 = 'y';
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>x2 : Symbol(x2, Decl(literalFreshnessPropagationOnNarrowing.ts, 32, 7))
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// Desired/actual: All OK
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let x3: XY = x;
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>x3 : Symbol(x3, Decl(literalFreshnessPropagationOnNarrowing.ts, 39, 7))
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>XY : Symbol(XY, Decl(literalFreshnessPropagationOnNarrowing.ts, 29, 15))
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>x : Symbol(x, Decl(literalFreshnessPropagationOnNarrowing.ts, 31, 9))
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x3 = 'y';
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>x3 : Symbol(x3, Decl(literalFreshnessPropagationOnNarrowing.ts, 39, 7))
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}
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function f4() {
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>f4 : Symbol(f4, Decl(literalFreshnessPropagationOnNarrowing.ts, 41, 1))
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const x: boolean = true;
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>x : Symbol(x, Decl(literalFreshnessPropagationOnNarrowing.ts, 44, 9))
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let x1 = x;
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>x1 : Symbol(x1, Decl(literalFreshnessPropagationOnNarrowing.ts, 45, 7))
|
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>x : Symbol(x, Decl(literalFreshnessPropagationOnNarrowing.ts, 44, 9))
|
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// Desired: OK
|
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// 3.0: OK
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// 3.1: OK
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// 3.1 minus widening propagation: error
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x1 = false;
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>x1 : Symbol(x1, Decl(literalFreshnessPropagationOnNarrowing.ts, 45, 7))
|
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}
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|
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function f5() {
|
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>f5 : Symbol(f5, Decl(literalFreshnessPropagationOnNarrowing.ts, 51, 1))
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|
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type XY = 'x' | 'y';
|
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>XY : Symbol(XY, Decl(literalFreshnessPropagationOnNarrowing.ts, 53, 15))
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|
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let arr: XY[] = ['x'];
|
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>arr : Symbol(arr, Decl(literalFreshnessPropagationOnNarrowing.ts, 55, 7))
|
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>XY : Symbol(XY, Decl(literalFreshnessPropagationOnNarrowing.ts, 53, 15))
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|
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arr = ['y'];
|
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>arr : Symbol(arr, Decl(literalFreshnessPropagationOnNarrowing.ts, 55, 7))
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|
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// Desired: OK
|
||||
// Error in all extant branches
|
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arr = [...['y']];
|
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>arr : Symbol(arr, Decl(literalFreshnessPropagationOnNarrowing.ts, 55, 7))
|
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}
|
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|
|
@ -0,0 +1,175 @@
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=== tests/cases/compiler/literalFreshnessPropagationOnNarrowing.ts ===
|
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function f1() {
|
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>f1 : () => void
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|
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let b = true;
|
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>b : boolean
|
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>true : true
|
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|
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let obj = { b };
|
||||
>obj : { b: boolean; }
|
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>{ b } : { b: boolean; }
|
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>b : boolean
|
||||
|
||||
// Desired: OK
|
||||
// 3.0: OK
|
||||
// 3.1 as-is: OK
|
||||
// 3.1 minus widening propagation: error
|
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obj.b = false;
|
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>obj.b = false : false
|
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>obj.b : boolean
|
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>obj : { b: boolean; }
|
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>b : boolean
|
||||
>false : false
|
||||
}
|
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|
||||
function f2() {
|
||||
>f2 : () => void
|
||||
|
||||
type Element = (string | false);
|
||||
>Element : string | false
|
||||
>false : false
|
||||
|
||||
type ElementOrArray = Element | Element[];
|
||||
>ElementOrArray : string | false | (string | false)[]
|
||||
|
||||
let el: Element = null as any;
|
||||
>el : string | false
|
||||
>null as any : any
|
||||
>null : null
|
||||
|
||||
let arr: Element[] = null as any;
|
||||
>arr : (string | false)[]
|
||||
>null as any : any
|
||||
>null : null
|
||||
|
||||
let elOrA: ElementOrArray = null as any;
|
||||
>elOrA : string | false | (string | false)[]
|
||||
>null as any : any
|
||||
>null : null
|
||||
|
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// Desired/actual: All OK
|
||||
let a1: ElementOrArray = el;
|
||||
>a1 : string | false | (string | false)[]
|
||||
>el : string | false
|
||||
|
||||
let a2: ElementOrArray = arr;
|
||||
>a2 : string | false | (string | false)[]
|
||||
>arr : (string | false)[]
|
||||
|
||||
let a3: ElementOrArray = [el];
|
||||
>a3 : string | false | (string | false)[]
|
||||
>[el] : (string | false)[]
|
||||
>el : string | false
|
||||
|
||||
let a4: ElementOrArray = Array.isArray(elOrA) ? elOrA : [elOrA];
|
||||
>a4 : string | false | (string | false)[]
|
||||
>Array.isArray(elOrA) ? elOrA : [elOrA] : (string | false)[]
|
||||
>Array.isArray(elOrA) : boolean
|
||||
>Array.isArray : (arg: any) => arg is any[]
|
||||
>Array : ArrayConstructor
|
||||
>isArray : (arg: any) => arg is any[]
|
||||
>elOrA : string | false | (string | false)[]
|
||||
>elOrA : (string | false)[]
|
||||
>[elOrA] : (string | false)[]
|
||||
>elOrA : string | false
|
||||
|
||||
// Desired: OK
|
||||
// 3.0: Error
|
||||
// 3.1: OK
|
||||
let a5: ElementOrArray = [...Array.isArray(elOrA) ? elOrA : [elOrA]];
|
||||
>a5 : string | false | (string | false)[]
|
||||
>[...Array.isArray(elOrA) ? elOrA : [elOrA]] : (string | false)[]
|
||||
>...Array.isArray(elOrA) ? elOrA : [elOrA] : string | false
|
||||
>Array.isArray(elOrA) ? elOrA : [elOrA] : (string | false)[]
|
||||
>Array.isArray(elOrA) : boolean
|
||||
>Array.isArray : (arg: any) => arg is any[]
|
||||
>Array : ArrayConstructor
|
||||
>isArray : (arg: any) => arg is any[]
|
||||
>elOrA : string | false | (string | false)[]
|
||||
>elOrA : (string | false)[]
|
||||
>[elOrA] : (string | false)[]
|
||||
>elOrA : string | false
|
||||
}
|
||||
|
||||
function f3() {
|
||||
>f3 : () => void
|
||||
|
||||
type XY = 'x' | 'y';
|
||||
>XY : "x" | "y"
|
||||
|
||||
const x: XY = 'x';
|
||||
>x : "x" | "y"
|
||||
>'x' : "x"
|
||||
|
||||
let x2 = x;
|
||||
>x2 : "x"
|
||||
>x : "x"
|
||||
|
||||
// Desired: OK (up for debate?)
|
||||
// 3.0: Error
|
||||
// 3.1 as-is: OK
|
||||
x2 = 'y';
|
||||
>x2 = 'y' : "y"
|
||||
>x2 : "x"
|
||||
>'y' : "y"
|
||||
|
||||
// Desired/actual: All OK
|
||||
let x3: XY = x;
|
||||
>x3 : "x" | "y"
|
||||
>x : "x"
|
||||
|
||||
x3 = 'y';
|
||||
>x3 = 'y' : "y"
|
||||
>x3 : "x" | "y"
|
||||
>'y' : "y"
|
||||
}
|
||||
|
||||
function f4() {
|
||||
>f4 : () => void
|
||||
|
||||
const x: boolean = true;
|
||||
>x : boolean
|
||||
>true : true
|
||||
|
||||
let x1 = x;
|
||||
>x1 : boolean
|
||||
>x : true
|
||||
|
||||
// Desired: OK
|
||||
// 3.0: OK
|
||||
// 3.1: OK
|
||||
// 3.1 minus widening propagation: error
|
||||
x1 = false;
|
||||
>x1 = false : false
|
||||
>x1 : boolean
|
||||
>false : false
|
||||
}
|
||||
|
||||
function f5() {
|
||||
>f5 : () => void
|
||||
|
||||
type XY = 'x' | 'y';
|
||||
>XY : "x" | "y"
|
||||
|
||||
let arr: XY[] = ['x'];
|
||||
>arr : ("x" | "y")[]
|
||||
>['x'] : "x"[]
|
||||
>'x' : "x"
|
||||
|
||||
arr = ['y'];
|
||||
>arr = ['y'] : "y"[]
|
||||
>arr : ("x" | "y")[]
|
||||
>['y'] : "y"[]
|
||||
>'y' : "y"
|
||||
|
||||
// Desired: OK
|
||||
// Error in all extant branches
|
||||
arr = [...['y']];
|
||||
>arr = [...['y']] : string[]
|
||||
>arr : ("x" | "y")[]
|
||||
>[...['y']] : string[]
|
||||
>...['y'] : string
|
||||
>['y'] : string[]
|
||||
>'y' : "y"
|
||||
}
|
||||
|
|
@ -0,0 +1,61 @@
|
|||
function f1() {
|
||||
let b = true;
|
||||
let obj = { b };
|
||||
// Desired: OK
|
||||
// 3.0: OK
|
||||
// 3.1 as-is: OK
|
||||
// 3.1 minus widening propagation: error
|
||||
obj.b = false;
|
||||
}
|
||||
|
||||
function f2() {
|
||||
type Element = (string | false);
|
||||
type ElementOrArray = Element | Element[];
|
||||
let el: Element = null as any;
|
||||
let arr: Element[] = null as any;
|
||||
let elOrA: ElementOrArray = null as any;
|
||||
|
||||
// Desired/actual: All OK
|
||||
let a1: ElementOrArray = el;
|
||||
let a2: ElementOrArray = arr;
|
||||
let a3: ElementOrArray = [el];
|
||||
let a4: ElementOrArray = Array.isArray(elOrA) ? elOrA : [elOrA];
|
||||
|
||||
// Desired: OK
|
||||
// 3.0: Error
|
||||
// 3.1: OK
|
||||
let a5: ElementOrArray = [...Array.isArray(elOrA) ? elOrA : [elOrA]];
|
||||
}
|
||||
|
||||
function f3() {
|
||||
type XY = 'x' | 'y';
|
||||
const x: XY = 'x';
|
||||
let x2 = x;
|
||||
// Desired: OK (up for debate?)
|
||||
// 3.0: Error
|
||||
// 3.1 as-is: OK
|
||||
x2 = 'y';
|
||||
|
||||
// Desired/actual: All OK
|
||||
let x3: XY = x;
|
||||
x3 = 'y';
|
||||
}
|
||||
|
||||
function f4() {
|
||||
const x: boolean = true;
|
||||
let x1 = x;
|
||||
// Desired: OK
|
||||
// 3.0: OK
|
||||
// 3.1: OK
|
||||
// 3.1 minus widening propagation: error
|
||||
x1 = false;
|
||||
}
|
||||
|
||||
function f5() {
|
||||
type XY = 'x' | 'y';
|
||||
let arr: XY[] = ['x'];
|
||||
arr = ['y'];
|
||||
// Desired: OK
|
||||
// Error in all extant branches
|
||||
arr = [...['y']];
|
||||
}
|
||||
Loading…
Reference in a new issue