feat(parameters): review types and exports (#1528)

* feat: base types

* chore: getMultiple void return

* wip: ssm/dynamo

* chore: add missing await

* fix: types import in ssm

* feat: imports

* feat: imports

* tests: coverage

* refactor: transformValue

* chore: test coverage for commons

* docs: typedocs

* chore: remove isUint8Array for nodejs14 compat

* docs: explained transformValue fn

Author: dreamorosi

packages/commons/src/index.ts

@@ -4,3 +4,4 @@ export * from './config';
 export * as ContextExamples from './samples/resources/contexts';
 export * as Events from './samples/resources/events';
 export * from './types/middy';
+export * from './types/utils';

packages/commons/src/types/utils.ts

@@ -0,0 +1,59 @@
+/**
+ * Returns true if the passed value is a record (object).
+ *
+ * @param value
+ */
+const isRecord = (value: unknown): value is Record<string, unknown> => {
+  return (
+    Object.prototype.toString.call(value) === '[object Object]' &&
+    !Object.is(value, null)
+  );
+};
+
+/**
+ * Returns true if the passed value is truthy.
+ *
+ * @param value
+ */
+const isTruthy = (value: unknown): boolean => {
+  if (typeof value === 'string') {
+    return value !== '';
+  } else if (typeof value === 'number') {
+    return value !== 0;
+  } else if (typeof value === 'boolean') {
+    return value;
+  } else if (Array.isArray(value)) {
+    return value.length > 0;
+  } else if (isRecord(value)) {
+    return Object.keys(value).length > 0;
+  } else {
+    return false;
+  }
+};
+
+/**
+ * Returns true if the passed value is null or undefined.
+ *
+ * @param value
+ */
+const isNullOrUndefined = (value: unknown): value is null | undefined => {
+  return Object.is(value, null) || Object.is(value, undefined);
+};
+
+/**
+ * Returns true if the passed value is a string.
+ * @param value
+ * @returns
+ */
+const isString = (value: unknown): value is string => {
+  return typeof value === 'string';
+};
+
+export { isRecord, isString, isTruthy, isNullOrUndefined };
+
+type JSONPrimitive = string | number | boolean | null | undefined;
+type JSONValue = JSONPrimitive | JSONObject | JSONArray;
+type JSONObject = { [key: string]: JSONValue };
+type JSONArray = Array<JSONValue>;
+
+export type { JSONPrimitive, JSONValue, JSONObject, JSONArray };