fix fragment resolving behavior with jsx: preserve and `jsxFragment…

…Factory: null` (#60122)

src/compiler/checker.ts

@@ -29873,10 +29873,10 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             const jsxFactoryNamespace = getJsxNamespace(node);
             const jsxFactoryLocation = isJsxOpeningLikeElement(node) ? node.tagName : node;
 
-            // allow null as jsxFragmentFactory
+            // #38720/60122, allow null as jsxFragmentFactory
             let jsxFactorySym: Symbol | undefined;
             if (!(isJsxOpeningFragment(node) && jsxFactoryNamespace === "null")) {
-                jsxFactorySym = resolveName(jsxFactoryLocation, jsxFactoryNamespace, SymbolFlags.Value, jsxFactoryRefErr, /*isUse*/ true);
+                jsxFactorySym = resolveName(jsxFactoryLocation, jsxFactoryNamespace, compilerOptions.jsx === JsxEmit.Preserve ? SymbolFlags.Value & ~SymbolFlags.Enum : SymbolFlags.Value, jsxFactoryRefErr, /*isUse*/ true);
             }
 
             if (jsxFactorySym) {
@@ -29890,12 +29890,12 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 }
             }
 
-            // For JsxFragment, mark jsx pragma as referenced via resolveName
+            // if JsxFragment, additionally mark jsx pragma as referenced, since `getJsxNamespace` above would have resolved to only the fragment factory if they are distinct
             if (isJsxOpeningFragment(node)) {
                 const file = getSourceFileOfNode(node);
                 const localJsxNamespace = getLocalJsxNamespace(file);
                 if (localJsxNamespace) {
-                    resolveName(jsxFactoryLocation, localJsxNamespace, SymbolFlags.Value, jsxFactoryRefErr, /*isUse*/ true);
+                    resolveName(jsxFactoryLocation, localJsxNamespace, compilerOptions.jsx === JsxEmit.Preserve ? SymbolFlags.Value & ~SymbolFlags.Enum : SymbolFlags.Value, jsxFactoryRefErr, /*isUse*/ true);
                 }
             }
         }
@@ -32918,7 +32918,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
 
         checkJsxChildren(node);
-        return getJsxElementTypeAt(node) || anyType;
+        const jsxElementType = getJsxElementTypeAt(node);
+        return isErrorType(jsxElementType) ? anyType : jsxElementType;
     }
 
     function isHyphenatedJsxName(name: string | __String) {
@@ -36643,9 +36644,12 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         if (sourceFileLinks.jsxFragmentType !== undefined) return sourceFileLinks.jsxFragmentType;
 
         const jsxFragmentFactoryName = getJsxNamespace(node);
+        // #38720/60122, allow null as jsxFragmentFactory
+        if (jsxFragmentFactoryName === "null") return sourceFileLinks.jsxFragmentType = anyType;
+
         const jsxFactoryRefErr = diagnostics ? Diagnostics.Using_JSX_fragments_requires_fragment_factory_0_to_be_in_scope_but_it_could_not_be_found : undefined;
         const jsxFactorySymbol = getJsxNamespaceContainerForImplicitImport(node) ??
-            resolveName(node, jsxFragmentFactoryName, SymbolFlags.Value, /*nameNotFoundMessage*/ jsxFactoryRefErr, /*isUse*/ true);
+            resolveName(node, jsxFragmentFactoryName, compilerOptions.jsx === JsxEmit.Preserve ? SymbolFlags.Value & ~SymbolFlags.Enum : SymbolFlags.Value, /*nameNotFoundMessage*/ jsxFactoryRefErr, /*isUse*/ true);
 
         if (jsxFactorySymbol === undefined) return sourceFileLinks.jsxFragmentType = errorType;
         if (jsxFactorySymbol.escapedName === ReactNames.Fragment) return sourceFileLinks.jsxFragmentType = getTypeOfSymbol(jsxFactorySymbol);

tests/baselines/reference/inlineJsxAndJsxFragPragma.errors.txt

@@ -1,9 +1,6 @@
 preacty-no-fragment.tsx(5,12): error TS6133: 'Fragment' is declared but its value is never read.
 preacty-only-fragment-no-jsx.tsx(6,1): error TS2874: This JSX tag requires 'h' to be in scope, but it could not be found.
 snabbdomy-only-fragment-no-jsx.tsx(4,1): error TS2874: This JSX tag requires 'jsx' to be in scope, but it could not be found.
-snabbdomy-only-fragment-no-jsx.tsx(4,1): error TS2879: Using JSX fragments requires fragment factory 'null' to be in scope, but it could not be found.
-snabbdomy-only-fragment.tsx(4,1): error TS2879: Using JSX fragments requires fragment factory 'null' to be in scope, but it could not be found.
-snabbdomy.tsx(4,1): error TS2879: Using JSX fragments requires fragment factory 'null' to be in scope, but it could not be found.
 
 
 ==== renderer.d.ts (0 errors) ====
@@ -26,13 +23,11 @@ snabbdomy.tsx(4,1): error TS2879: Using JSX fragments requires fragment factory
     import {h, Fragment} from "./renderer";
     <><div></div></>
 
-==== snabbdomy.tsx (1 errors) ====
+==== snabbdomy.tsx (0 errors) ====
     /* @jsx jsx */
     /* @jsxfrag null */
     import {jsx} from "./renderer";
     <><span></span></>
-    ~~
-!!! error TS2879: Using JSX fragments requires fragment factory 'null' to be in scope, but it could not be found.
 
 ==== preacty-only-fragment.tsx (0 errors) ====
     /**
@@ -42,13 +37,11 @@ snabbdomy.tsx(4,1): error TS2879: Using JSX fragments requires fragment factory
     import {h, Fragment} from "./renderer";
     <></>
 
-==== snabbdomy-only-fragment.tsx (1 errors) ====
+==== snabbdomy-only-fragment.tsx (0 errors) ====
     /* @jsx jsx */
     /* @jsxfrag null */
     import {jsx} from "./renderer";
     <></>
-    ~~
-!!! error TS2879: Using JSX fragments requires fragment factory 'null' to be in scope, but it could not be found.
 
 ==== preacty-only-fragment-no-jsx.tsx (1 errors) ====
     /**
@@ -60,15 +53,13 @@ snabbdomy.tsx(4,1): error TS2879: Using JSX fragments requires fragment factory
     ~~
 !!! error TS2874: This JSX tag requires 'h' to be in scope, but it could not be found.
 
-==== snabbdomy-only-fragment-no-jsx.tsx (2 errors) ====
+==== snabbdomy-only-fragment-no-jsx.tsx (1 errors) ====
     /* @jsx jsx */
     /* @jsxfrag null */
     import {} from "./renderer";
     <></>
     ~~
 !!! error TS2874: This JSX tag requires 'jsx' to be in scope, but it could not be found.
-    ~~
-!!! error TS2879: Using JSX fragments requires fragment factory 'null' to be in scope, but it could not be found.
 
 ==== preacty-no-fragment.tsx (1 errors) ====
     /**

tests/baselines/reference/inlineJsxAndJsxFragPragmaOverridesCompilerOptions.types

@@ -44,9 +44,7 @@ import {createElement, Fragment} from "./react";
 
 <><span></span></>
 ><><span></span></> : any
->                   : ^^^
-><span></span> : any
->              : ^^^
+><span></span> : error
 >span : any
 >     : ^^^
 >span : any
@@ -65,9 +63,7 @@ import {h, Frag} from "./preact";
 
 <><div></div></>
 ><><div></div></> : any
->                 : ^^^
-><div></div> : any
->            : ^^^
+><div></div> : error
 >div : any
 >    : ^^^
 >div : any
@@ -84,9 +80,7 @@ import {h} from "./snabbdom";
 
 <><div></div></>
 ><><div></div></> : any
->                 : ^^^
-><div></div> : any
->            : ^^^
+><div></div> : error
 >div : any
 >    : ^^^
 >div : any
@@ -105,9 +99,7 @@ import {Fragment} from "./react";
 
 <><span></span></>
 ><><span></span></> : any
->                   : ^^^
-><span></span> : any
->              : ^^^
+><span></span> : error
 >span : any
 >     : ^^^
 >span : any

tests/baselines/reference/jsxFactoryAndJsxFragmentFactory.types

@@ -8,16 +8,16 @@ declare var Frag: any;
 >Frag : any
 
 <></>;
-><></> : error
+><></> : any
 
 <><span>1</span><><span>2.1</span><span>2.2</span></></>;
-><><span>1</span><><span>2.1</span><span>2.2</span></></> : error
+><><span>1</span><><span>2.1</span><span>2.2</span></></> : any
 ><span>1</span> : error
 >span : any
 >     : ^^^
 >span : any
 >     : ^^^
-><><span>2.1</span><span>2.2</span></> : error
+><><span>2.1</span><span>2.2</span></> : any
 ><span>2.1</span> : error
 >span : any
 >     : ^^^

tests/baselines/reference/jsxFactoryAndJsxFragmentFactoryNull.types

@@ -3,31 +3,24 @@
 === jsxFactoryAndJsxFragmentFactoryNull.tsx ===
 declare var h: any;
 >h : any
->  : ^^^
 
 <></>;
 ><></> : any
->      : ^^^
 
 <><span>1</span><><span>2.1</span><span>2.2</span></></>;
 ><><span>1</span><><span>2.1</span><span>2.2</span></></> : any
->                                                         : ^^^
-><span>1</span> : any
->               : ^^^
+><span>1</span> : error
 >span : any
 >     : ^^^
 >span : any
 >     : ^^^
 ><><span>2.1</span><span>2.2</span></> : any
->                                      : ^^^
-><span>2.1</span> : any
->                 : ^^^
+><span>2.1</span> : error
 >span : any
 >     : ^^^
 >span : any
 >     : ^^^
-><span>2.2</span> : any
->                 : ^^^
+><span>2.2</span> : error
 >span : any
 >     : ^^^
 >span : any