jsx option affects emit (#40775)

src/compiler/commandLineParser.ts

@@ -380,6 +380,7 @@ namespace ts {
             name: "jsx",
             type: jsxOptionMap,
             affectsSourceFile: true,
+            affectsEmit: true,
             paramType: Diagnostics.KIND,
             showInSimplifiedHelpView: true,
             category: Diagnostics.Basic_Options,

src/testRunner/unittests/tscWatch/programUpdates.ts

@@ -1598,5 +1598,33 @@ import { x } from "../b";`),
                 },
             ]
         });
+
+        verifyTscWatch({
+            scenario,
+            subScenario: "updates emit on jsx option change",
+            commandLineArgs: ["-w"],
+            sys: () => {
+                const index: File = {
+                    path: `${projectRoot}/index.tsx`,
+                    content: `declare var React: any;\nconst d = <div />;`
+                };
+                const configFile: File = {
+                    path: `${projectRoot}/tsconfig.json`,
+                    content: JSON.stringify({
+                        compilerOptions: {
+                            jsx: "preserve"
+                        }
+                    })
+                };
+                return createWatchedSystem([index, configFile, libFile], { currentDirectory: projectRoot });
+            },
+            changes: [
+                {
+                    caption: "Update 'jsx' to 'react'",
+                    change: sys => sys.writeFile(`${projectRoot}/tsconfig.json`, '{ "compilerOptions": { "jsx": "react" } }'),
+                    timeouts: runQueuedTimeoutCallbacks,
+                },
+            ]
+        });
     });
 }

tests/baselines/reference/tscWatch/programUpdates/updates-emit-on-jsx-option-change.js

@@ -0,0 +1,109 @@
+Input::
+//// [/user/username/projects/myproject/index.tsx]
+declare var React: any;
+const d = <div />;
+
+//// [/user/username/projects/myproject/tsconfig.json]
+{"compilerOptions":{"jsx":"preserve"}}
+
+//// [/a/lib/lib.d.ts]
+/// <reference no-default-lib="true"/>
+interface Boolean {}
+interface Function {}
+interface CallableFunction {}
+interface NewableFunction {}
+interface IArguments {}
+interface Number { toExponential: any; }
+interface Object {}
+interface RegExp {}
+interface String { charAt: any; }
+interface Array<T> { length: number; [n: number]: T; }
+
+
+/a/lib/tsc.js -w
+Output::
+>> Screen clear
+[12:00:21 AM] Starting compilation in watch mode...
+
+[12:00:24 AM] Found 0 errors. Watching for file changes.
+
+
+
+Program root files: ["/user/username/projects/myproject/index.tsx"]
+Program options: {"jsx":1,"watch":true,"configFilePath":"/user/username/projects/myproject/tsconfig.json"}
+Program files::
+/a/lib/lib.d.ts
+/user/username/projects/myproject/index.tsx
+
+Semantic diagnostics in builder refreshed for::
+/a/lib/lib.d.ts
+/user/username/projects/myproject/index.tsx
+
+WatchedFiles::
+/user/username/projects/myproject/tsconfig.json:
+  {"fileName":"/user/username/projects/myproject/tsconfig.json","pollingInterval":250}
+/user/username/projects/myproject/index.tsx:
+  {"fileName":"/user/username/projects/myproject/index.tsx","pollingInterval":250}
+/a/lib/lib.d.ts:
+  {"fileName":"/a/lib/lib.d.ts","pollingInterval":250}
+
+FsWatches::
+
+FsWatchesRecursive::
+/user/username/projects/myproject/node_modules/@types:
+  {"directoryName":"/user/username/projects/myproject/node_modules/@types","fallbackPollingInterval":500,"fallbackOptions":{"watchFile":"PriorityPollingInterval"}}
+/user/username/projects/myproject:
+  {"directoryName":"/user/username/projects/myproject","fallbackPollingInterval":500,"fallbackOptions":{"watchFile":"PriorityPollingInterval"}}
+
+exitCode:: ExitStatus.undefined
+
+//// [/user/username/projects/myproject/index.jsx]
+var d = <div />;
+
+
+
+Change:: Update 'jsx' to 'react'
+
+Input::
+//// [/user/username/projects/myproject/tsconfig.json]
+{ "compilerOptions": { "jsx": "react" } }
+
+
+Output::
+>> Screen clear
+[12:00:28 AM] File change detected. Starting incremental compilation...
+
+[12:00:31 AM] Found 0 errors. Watching for file changes.
+
+
+
+Program root files: ["/user/username/projects/myproject/index.tsx"]
+Program options: {"jsx":2,"watch":true,"configFilePath":"/user/username/projects/myproject/tsconfig.json"}
+Program files::
+/a/lib/lib.d.ts
+/user/username/projects/myproject/index.tsx
+
+Semantic diagnostics in builder refreshed for::
+
+WatchedFiles::
+/user/username/projects/myproject/tsconfig.json:
+  {"fileName":"/user/username/projects/myproject/tsconfig.json","pollingInterval":250}
+/user/username/projects/myproject/index.tsx:
+  {"fileName":"/user/username/projects/myproject/index.tsx","pollingInterval":250}
+/a/lib/lib.d.ts:
+  {"fileName":"/a/lib/lib.d.ts","pollingInterval":250}
+
+FsWatches::
+
+FsWatchesRecursive::
+/user/username/projects/myproject/node_modules/@types:
+  {"directoryName":"/user/username/projects/myproject/node_modules/@types","fallbackPollingInterval":500,"fallbackOptions":{"watchFile":"PriorityPollingInterval"}}
+/user/username/projects/myproject:
+  {"directoryName":"/user/username/projects/myproject","fallbackPollingInterval":500,"fallbackOptions":{"watchFile":"PriorityPollingInterval"}}
+
+exitCode:: ExitStatus.undefined
+
+//// [/user/username/projects/myproject/index.js]
+var d = React.createElement("div", null);
+
+