Switch from ajv to io-ts for config validation; validate configs on save in the API/dashboard; start work on creating io-ts schemas for all plugins

src/validatorUtils.ts

@@ -0,0 +1,27 @@
+import * as t from "io-ts";
+import { pipe } from "fp-ts/lib/pipeable";
+import { fold } from "fp-ts/lib/Either";
+import { PathReporter } from "io-ts/lib/PathReporter";
+
+/**
+ * Validates the given value against the given schema while also disallowing extra properties
+ * See: https://github.com/gcanti/io-ts/issues/322
+ */
+export function validateStrict(schema: t.Type<any, any, any>, value: any): string[] | null {
+  const validationResult = schema.decode(value);
+  return pipe(
+    validationResult,
+    fold(
+      err => PathReporter.report(validationResult),
+      result => {
+        // Make sure there are no extra properties
+        if (JSON.stringify(value) !== JSON.stringify(result)) {
+          // TODO: Actually mention what the unknown property is
+          return ["Found unknown properties"];
+        }
+
+        return null;
+      },
+    ),
+  );
+}