Correct tuple relations in --strictOptionalProperties mode (#44568)

* Fix relations for optional elements in tuples with --strictOptionalProperties

* Accept new baselines

* Add regression test

* Address CR feedback

src/compiler/checker.ts

@@ -15095,11 +15095,11 @@ namespace ts {
         }
 
         function isTypicalNondistributiveConditional(root: ConditionalRoot) {
-            return !root.isDistributive
-                && root.node.checkType.kind === SyntaxKind.TupleType
-                && length((root.node.checkType as TupleTypeNode).elements) === 1
-                && root.node.extendsType.kind === SyntaxKind.TupleType
-                && length((root.node.extendsType as TupleTypeNode).elements) === 1;
+            return !root.isDistributive && isSingletonTupleType(root.node.checkType) && isSingletonTupleType(root.node.extendsType);
+        }
+
+        function isSingletonTupleType(node: TypeNode) {
+            return isTupleTypeNode(node) && length(node.elements) === 1 && !isOptionalTypeNode(node.elements[0]) && !isRestTypeNode(node.elements[0]);
         }
 
         /**
@@ -18711,7 +18711,7 @@ namespace ts {
                         return Ternary.False;
                     }
                     if (getObjectFlags(source) & ObjectFlags.Reference && getObjectFlags(target) & ObjectFlags.Reference && (source as TypeReference).target === (target as TypeReference).target &&
-                        !(getObjectFlags(source) & ObjectFlags.MarkerType || getObjectFlags(target) & ObjectFlags.MarkerType)) {
+                        !isTupleType(source) && !(getObjectFlags(source) & ObjectFlags.MarkerType || getObjectFlags(target) & ObjectFlags.MarkerType)) {
                         // We have type references to the same generic type, and the type references are not marker
                         // type references (which are intended by be compared structurally). Obtain the variance
                         // information for the type parameters and relate the type arguments accordingly.
@@ -19182,7 +19182,7 @@ namespace ts {
                                 removeMissingType(targetType, !!(targetFlags & ElementFlags.Optional));
                             const related = isRelatedTo(sourceType, targetCheckType, reportErrors, /*headMessage*/ undefined, intersectionState);
                             if (!related) {
-                                if (reportErrors) {
+                                if (reportErrors && (targetArity > 1 || sourceArity > 1)) {
                                     if (i < startCount || i >= targetArity - endCount || sourceArity - startCount - endCount === 1) {
                                         reportIncompatibleError(Diagnostics.Type_at_position_0_in_source_is_not_compatible_with_type_at_position_1_in_target, sourceIndex, i);
                                     }

tests/baselines/reference/arityAndOrderCompatibility01.errors.txt

@@ -21,7 +21,8 @@ tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(28,5): error
     Type '2' is not assignable to type '1'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(29,5): error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[string]'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(30,5): error TS2322: Type '[string, number]' is not assignable to type '[number, string]'.
-  Type 'string' is not assignable to type 'number'.
+  Type at position 0 in source is not compatible with type at position 0 in target.
+    Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(31,5): error TS2322: Type 'StrNum' is not assignable to type '[number, string]'.
   Types of property '0' are incompatible.
     Type 'string' is not assignable to type 'number'.
@@ -97,7 +98,8 @@ tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(32,5): error
     var n1: [number, string] = x;
         ~~
 !!! error TS2322: Type '[string, number]' is not assignable to type '[number, string]'.
-!!! error TS2322:   Type 'string' is not assignable to type 'number'.
+!!! error TS2322:   Type at position 0 in source is not compatible with type at position 0 in target.
+!!! error TS2322:     Type 'string' is not assignable to type 'number'.
     var n2: [number, string] = y;
         ~~
 !!! error TS2322: Type 'StrNum' is not assignable to type '[number, string]'.

tests/baselines/reference/castingTuple.errors.txt

@@ -7,9 +7,11 @@ tests/cases/conformance/types/tuple/castingTuple.ts(18,21): error TS2352: Conver
   Source has 2 element(s) but target requires 3.
 tests/cases/conformance/types/tuple/castingTuple.ts(20,33): error TS2493: Tuple type '[C, D, A]' of length '3' has no element at index '5'.
 tests/cases/conformance/types/tuple/castingTuple.ts(30,10): error TS2352: Conversion of type '[number, string]' to type '[number, number]' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.
-  Type 'string' is not comparable to type 'number'.
+  Type at position 1 in source is not compatible with type at position 1 in target.
+    Type 'string' is not comparable to type 'number'.
 tests/cases/conformance/types/tuple/castingTuple.ts(31,10): error TS2352: Conversion of type '[C, D]' to type '[A, I]' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.
-  Property 'a' is missing in type 'C' but required in type 'A'.
+  Type at position 0 in source is not compatible with type at position 0 in target.
+    Property 'a' is missing in type 'C' but required in type 'A'.
 tests/cases/conformance/types/tuple/castingTuple.ts(32,5): error TS2403: Subsequent variable declarations must have the same type.  Variable 'array1' must be of type '{}[]', but here has type 'number[]'.
 tests/cases/conformance/types/tuple/castingTuple.ts(33,1): error TS2304: Cannot find name 't4'.
 
@@ -60,11 +62,13 @@ tests/cases/conformance/types/tuple/castingTuple.ts(33,1): error TS2304: Cannot
     var t3 = <[number, number]>numStrTuple;
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2352: Conversion of type '[number, string]' to type '[number, number]' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.
-!!! error TS2352:   Type 'string' is not comparable to type 'number'.
+!!! error TS2352:   Type at position 1 in source is not compatible with type at position 1 in target.
+!!! error TS2352:     Type 'string' is not comparable to type 'number'.
     var t9 = <[A, I]>classCDTuple;
              ~~~~~~~~~~~~~~~~~~~~
 !!! error TS2352: Conversion of type '[C, D]' to type '[A, I]' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.
-!!! error TS2352:   Property 'a' is missing in type 'C' but required in type 'A'.
+!!! error TS2352:   Type at position 0 in source is not compatible with type at position 0 in target.
+!!! error TS2352:     Property 'a' is missing in type 'C' but required in type 'A'.
 !!! related TS2728 tests/cases/conformance/types/tuple/castingTuple.ts:2:11: 'a' is declared here.
     var array1 = <number[]>numStrTuple;
         ~~~~~~

tests/baselines/reference/contextualTypeWithTuple.errors.txt

@@ -12,8 +12,9 @@ tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts(23,1): error TS23
 tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts(24,1): error TS2322: Type '[C, string | number]' is not assignable to type '[C, string | number, D]'.
   Source has 2 element(s) but target requires 3.
 tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts(25,1): error TS2322: Type '[number, string | number]' is not assignable to type '[number, string]'.
-  Type 'string | number' is not assignable to type 'string'.
-    Type 'number' is not assignable to type 'string'.
+  Type at position 1 in source is not compatible with type at position 1 in target.
+    Type 'string | number' is not assignable to type 'string'.
+      Type 'number' is not assignable to type 'string'.
 
 
 ==== tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts (8 errors) ====
@@ -65,5 +66,6 @@ tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts(25,1): error TS23
     numStrTuple = unionTuple3;
     ~~~~~~~~~~~
 !!! error TS2322: Type '[number, string | number]' is not assignable to type '[number, string]'.
-!!! error TS2322:   Type 'string | number' is not assignable to type 'string'.
-!!! error TS2322:     Type 'number' is not assignable to type 'string'.
+!!! error TS2322:   Type at position 1 in source is not compatible with type at position 1 in target.
+!!! error TS2322:     Type 'string | number' is not assignable to type 'string'.
+!!! error TS2322:       Type 'number' is not assignable to type 'string'.

tests/baselines/reference/iterableArrayPattern29.errors.txt

@@ -1,5 +1,6 @@
 tests/cases/conformance/es6/destructuring/iterableArrayPattern29.ts(2,21): error TS2345: Argument of type '[string, boolean]' is not assignable to parameter of type '[string, number]'.
-  Type 'boolean' is not assignable to type 'number'.
+  Type at position 1 in source is not compatible with type at position 1 in target.
+    Type 'boolean' is not assignable to type 'number'.
 
 
 ==== tests/cases/conformance/es6/destructuring/iterableArrayPattern29.ts (1 errors) ====
@@ -7,4 +8,5 @@ tests/cases/conformance/es6/destructuring/iterableArrayPattern29.ts(2,21): error
     takeFirstTwoEntries(...new Map([["", true], ["hello", true]]));
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type '[string, boolean]' is not assignable to parameter of type '[string, number]'.
-!!! error TS2345:   Type 'boolean' is not assignable to type 'number'.
+!!! error TS2345:   Type at position 1 in source is not compatible with type at position 1 in target.
+!!! error TS2345:     Type 'boolean' is not assignable to type 'number'.

tests/baselines/reference/restTupleElements1.errors.txt

@@ -11,9 +11,11 @@ tests/cases/conformance/types/tuple/restTupleElements1.ts(29,18): error TS2344:
 tests/cases/conformance/types/tuple/restTupleElements1.ts(30,18): error TS2344: Type '[number, ...number[]]' does not satisfy the constraint '[number]'.
   Target allows only 1 element(s) but source may have more.
 tests/cases/conformance/types/tuple/restTupleElements1.ts(32,31): error TS2344: Type '[number, ...string[]]' does not satisfy the constraint '[number, ...number[]]'.
-  Type 'string' is not assignable to type 'number'.
+  Type at position 1 in source is not compatible with type at position 1 in target.
+    Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/types/tuple/restTupleElements1.ts(33,31): error TS2344: Type '[string, ...number[]]' does not satisfy the constraint '[number, ...number[]]'.
-  Type 'string' is not assignable to type 'number'.
+  Type at position 0 in source is not compatible with type at position 0 in target.
+    Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/types/tuple/restTupleElements1.ts(34,31): error TS2344: Type '[number, number, string]' does not satisfy the constraint '[number, ...number[]]'.
   Type at positions 1 through 2 in source is not compatible with type at position 1 in target.
     Type 'string | number' is not assignable to type 'number'.
@@ -81,11 +83,13 @@ tests/cases/conformance/types/tuple/restTupleElements1.ts(59,4): error TS2345: A
     assign<[number, ...number[]], [number, ...string[]]>();  // Error
                                   ~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2344: Type '[number, ...string[]]' does not satisfy the constraint '[number, ...number[]]'.
-!!! error TS2344:   Type 'string' is not assignable to type 'number'.
+!!! error TS2344:   Type at position 1 in source is not compatible with type at position 1 in target.
+!!! error TS2344:     Type 'string' is not assignable to type 'number'.
     assign<[number, ...number[]], [string, ...number[]]>();  // Error
                                   ~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2344: Type '[string, ...number[]]' does not satisfy the constraint '[number, ...number[]]'.
-!!! error TS2344:   Type 'string' is not assignable to type 'number'.
+!!! error TS2344:   Type at position 0 in source is not compatible with type at position 0 in target.
+!!! error TS2344:     Type 'string' is not assignable to type 'number'.
     assign<[number, ...number[]], [number, number, string]>();  // Error
                                   ~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2344: Type '[number, number, string]' does not satisfy the constraint '[number, ...number[]]'.

tests/baselines/reference/strictOptionalProperties2.js

@@ -0,0 +1,19 @@
+//// [strictOptionalProperties2.ts]
+// Repro from #44567
+
+type T1 = { 0?: string | undefined } extends { 0?: string } ? true : false;  // false
+type T2 = [(string | undefined)?] extends [string?] ? true : false;  // false
+
+
+//// [strictOptionalProperties2.js]
+"use strict";
+// Repro from #44567
+
+
+//// [strictOptionalProperties2.d.ts]
+declare type T1 = {
+    0?: string | undefined;
+} extends {
+    0?: string;
+} ? true : false;
+declare type T2 = [(string | undefined)?] extends [string?] ? true : false;

tests/baselines/reference/strictOptionalProperties2.symbols

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/strictOptionalProperties2.ts ===
+// Repro from #44567
+
+type T1 = { 0?: string | undefined } extends { 0?: string } ? true : false;  // false
+>T1 : Symbol(T1, Decl(strictOptionalProperties2.ts, 0, 0))
+>0 : Symbol(0, Decl(strictOptionalProperties2.ts, 2, 11))
+>0 : Symbol(0, Decl(strictOptionalProperties2.ts, 2, 46))
+
+type T2 = [(string | undefined)?] extends [string?] ? true : false;  // false
+>T2 : Symbol(T2, Decl(strictOptionalProperties2.ts, 2, 75))
+

tests/baselines/reference/strictOptionalProperties2.types

@@ -0,0 +1,15 @@
+=== tests/cases/compiler/strictOptionalProperties2.ts ===
+// Repro from #44567
+
+type T1 = { 0?: string | undefined } extends { 0?: string } ? true : false;  // false
+>T1 : false
+>0 : string | undefined
+>0 : string | undefined
+>true : true
+>false : false
+
+type T2 = [(string | undefined)?] extends [string?] ? true : false;  // false
+>T2 : false
+>true : true
+>false : false
+

tests/baselines/reference/tupleTypes.errors.txt

@@ -18,9 +18,11 @@ tests/cases/compiler/tupleTypes.ts(49,1): error TS2322: Type '[number, {}]' is n
   Type 'number | {}' is not assignable to type 'number'.
     Type '{}' is not assignable to type 'number'.
 tests/cases/compiler/tupleTypes.ts(50,1): error TS2322: Type '[number, number]' is not assignable to type '[number, string]'.
-  Type 'number' is not assignable to type 'string'.
+  Type at position 1 in source is not compatible with type at position 1 in target.
+    Type 'number' is not assignable to type 'string'.
 tests/cases/compiler/tupleTypes.ts(51,1): error TS2322: Type '[number, {}]' is not assignable to type '[number, string]'.
-  Type '{}' is not assignable to type 'string'.
+  Type at position 1 in source is not compatible with type at position 1 in target.
+    Type '{}' is not assignable to type 'string'.
 
 
 ==== tests/cases/compiler/tupleTypes.ts (14 errors) ====
@@ -109,11 +111,13 @@ tests/cases/compiler/tupleTypes.ts(51,1): error TS2322: Type '[number, {}]' is n
     a1 = a2;  // Error
     ~~
 !!! error TS2322: Type '[number, number]' is not assignable to type '[number, string]'.
-!!! error TS2322:   Type 'number' is not assignable to type 'string'.
+!!! error TS2322:   Type at position 1 in source is not compatible with type at position 1 in target.
+!!! error TS2322:     Type 'number' is not assignable to type 'string'.
     a1 = a3;  // Error
     ~~
 !!! error TS2322: Type '[number, {}]' is not assignable to type '[number, string]'.
-!!! error TS2322:   Type '{}' is not assignable to type 'string'.
+!!! error TS2322:   Type at position 1 in source is not compatible with type at position 1 in target.
+!!! error TS2322:     Type '{}' is not assignable to type 'string'.
     a3 = a1;
     a3 = a2;
     

tests/baselines/reference/variadicTuples1.errors.txt

@@ -9,8 +9,9 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(149,5): error TS2322: Typ
 tests/cases/conformance/types/tuple/variadicTuples1.ts(151,5): error TS2322: Type '[string, ...unknown[]]' is not assignable to type '[string, ...U]'.
   Target requires 2 element(s) but source may have fewer.
 tests/cases/conformance/types/tuple/variadicTuples1.ts(152,5): error TS2322: Type '[string, ...T]' is not assignable to type '[string, ...U]'.
-  Type 'T' is not assignable to type 'U'.
-    'T' is assignable to the constraint of type 'U', but 'U' could be instantiated with a different subtype of constraint 'string[]'.
+  Type at position 1 in source is not compatible with type at position 1 in target.
+    Type 'T' is not assignable to type 'U'.
+      'T' is assignable to the constraint of type 'U', but 'U' could be instantiated with a different subtype of constraint 'string[]'.
 tests/cases/conformance/types/tuple/variadicTuples1.ts(160,5): error TS2322: Type 'readonly [...T]' is not assignable to type 'T'.
   'T' could be instantiated with an arbitrary type which could be unrelated to 'readonly [...T]'.
 tests/cases/conformance/types/tuple/variadicTuples1.ts(162,5): error TS4104: The type 'readonly [...T]' is 'readonly' and cannot be assigned to the mutable type '[...T]'.
@@ -212,8 +213,9 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(397,7): error TS2322: Typ
         z = y;  // Error
         ~
 !!! error TS2322: Type '[string, ...T]' is not assignable to type '[string, ...U]'.
-!!! error TS2322:   Type 'T' is not assignable to type 'U'.
-!!! error TS2322:     'T' is assignable to the constraint of type 'U', but 'U' could be instantiated with a different subtype of constraint 'string[]'.
+!!! error TS2322:   Type at position 1 in source is not compatible with type at position 1 in target.
+!!! error TS2322:     Type 'T' is not assignable to type 'U'.
+!!! error TS2322:       'T' is assignable to the constraint of type 'U', but 'U' could be instantiated with a different subtype of constraint 'string[]'.
     }
     
     // For a generic type T, [...T] is assignable to T, T is assignable to readonly [...T], and T is assignable

tests/cases/compiler/strictOptionalProperties2.ts

@@ -0,0 +1,7 @@
+// @strict: true
+// @declaration: true
+
+// Repro from #44567
+
+type T1 = { 0?: string | undefined } extends { 0?: string } ? true : false;  // false
+type T2 = [(string | undefined)?] extends [string?] ? true : false;  // false