(core) move home server into core

Summary: This moves enough server material into core to run a home server.  The data engine is not yet incorporated (though in manual testing it works when ported).

Test Plan: existing tests pass

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2552

app/gen-server/lib/values.ts

@@ -0,0 +1,36 @@
+/**
+ * This smoothes over some awkward differences between TypeORM treatment of
+ * booleans and json in sqlite and postgres.  Booleans and json work fine
+ * with each db, but have different levels of driver-level support.
+ */
+
+export interface NativeValues {
+  // Json columns are handled natively by the postgres driver, but for
+  // sqlite requires a typeorm wrapper (simple-json).
+  jsonEntityType: 'json' | 'simple-json';
+  jsonType: 'json' | 'varchar';
+  booleanType: 'boolean' | 'integer';
+  dateTimeType: 'timestamp with time zone' | 'datetime';
+  trueValue: boolean | number;
+  falseValue: boolean | number;
+}
+
+const sqliteNativeValues: NativeValues = {
+  jsonEntityType: 'simple-json',
+  jsonType: 'varchar',
+  booleanType: 'integer',
+  dateTimeType: 'datetime',
+  trueValue: 1,
+  falseValue: 0
+};
+
+const postgresNativeValues: NativeValues = {
+  jsonEntityType: 'json',
+  jsonType: 'json',
+  booleanType: 'boolean',
+  dateTimeType: 'timestamp with time zone',
+  trueValue: true,
+  falseValue: false
+};
+
+export const nativeValues = (process.env.TYPEORM_TYPE === 'postgres') ? postgresNativeValues : sqliteNativeValues;