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/util/dataframe/util.js

@@ -1,64 +0,0 @@
-/*
-Private utility code for dataframe
-*/
-
-export { isTypedArray, isArrayOrTypedArray } from "../typeHelpers";
-
-export function callOnceLazy(f) {
-  /*
-  call function once, and save the result, regardless of arguments (this is not
-  the same as typical memoization).
-  */
-  let value;
-  let calledOnce = false;
-  const result = function result(...args) {
-    if (!calledOnce) {
-      value = f(...args);
-      calledOnce = true;
-    }
-    return value;
-  };
-  return result;
-}
-
-export function memoize(fn, hashFn, maxResultsCached = -1) {
-  /* 
-  function memoization, with user-provided hash.  hashFn must return a
-  key which will be unique as a Map key (ie, obeys "sameValueZero" algorithm
-  as defined in the JS spec).  For more info on hash key, see:
-  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map#Key_equality
-  */
-  const cache = new Map();
-  const wrap = function wrap(...args) {
-    const key = hashFn(...args);
-    if (cache.has(key)) {
-      return cache.get(key);
-    }
-    const result = fn(...args);
-    cache.set(key, result);
-
-    if (maxResultsCached > -1 && cache.size > maxResultsCached) {
-      /* Least recent insertion deletion */
-      cache.delete(cache.keys().next().value);
-    }
-
-    return result;
-  };
-
-  wrap.clear = function clear() {
-    /* clear memoization cache */
-    cache.clear();
-  };
-
-  return wrap;
-}
-
-/**
-memoization helpers - just a global counter.
-**/
-let __DataframeMemoId__ = 0;
-export function __getMemoId() {
-  const id = __DataframeMemoId__;
-  __DataframeMemoId__ += 1;
-  return id;
-}