TS migration. #2288. (#2328)

* Added TS. Updated build and linting config. Added types.

* [ts-migrate][.] Rename files from JS/JSX to TS/TSX

Co-authored-by: ts-migrate <>

* [ts-migrate][.] Run TS Migrate

Co-authored-by: ts-migrate <>

* Corrected files mangled by ts-migrate.

* Updated lint config, minor linting.

* Re-enabled Husky.

* Updated tests and config.

* Reverted webpack devtool config.

* Removed obsolete snapshots.

* Added annotations snap.

* Updated tsconfig includes wrt linting.

* Removed ts-migrate.

Co-authored-by: Timmy Huang <tihuan@users.noreply.github.com>

client/src/reducers/continuousSelection.ts

@@ -0,0 +1,37 @@
+import { makeContinuousDimensionName } from "../util/nameCreators";
+
+const ContinuousSelection = (state = {}, action: any) => {
+  switch (action.type) {
+    case "reset subset":
+    case "subset to selection":
+    case "set clip quantiles": {
+      return {};
+    }
+    case "continuous metadata histogram start":
+    case "continuous metadata histogram brush":
+    case "continuous metadata histogram end": {
+      const name = makeContinuousDimensionName(
+        action.continuousNamespace,
+        action.selection
+      );
+      return {
+        ...state,
+        [name]: action.range,
+      };
+    }
+    case "continuous metadata histogram cancel": {
+      const name = makeContinuousDimensionName(
+        action.continuousNamespace,
+        action.selection
+      );
+      // @ts-expect-error ts-migrate(2537) FIXME: Type '{}' has no matching index signature for type... Remove this comment to see the full error message
+      const { [name]: deletedField, ...newState } = state;
+      return newState;
+    }
+    default: {
+      return state;
+    }
+  }
+};
+
+export default ContinuousSelection;