Merge pull request #1735 from constructive-io/feat/pg-client-select-exclusions

feat(pg-codegen): state a select as exclusions, not only a key list

Author: pyramation

postgres/pg-codegen/__fixtures__/generated/client.ts

@@ -33,18 +33,38 @@ export interface TableSpec<App> {
   jsonFields?: readonly string[];
 }
 
-/** Select shape: `{ id: true, name: true }` — same as the GraphQL ORM. */
+/**
+ * Select shape — same as the GraphQL ORM, stated either way round:
+ *
+ * - `{ id: true, name: true }` reads those fields and nothing else;
+ * - `{ databaseId: false }` reads every field except that one, for the field a
+ *   record has in general but this binding's table does not (a scope's copy of
+ *   a table without the scope key column) or that a caller must not carry (a
+ *   secret's id, row bookkeeping).
+ *
+ * Naming a field `true` is a projection and wins outright: the excluded ones
+ * are simply not in it.
+ */
 export type SelectShape<App> = { [K in keyof App]?: boolean };
 
 type TrueKeys<App, S> = {
   [K in keyof S]-?: S[K] extends true ? K & keyof App : never;
 }[keyof S];
 
-/** Rows narrow to the selected fields; no `select` returns the full record. */
+type FalseKeys<App, S> = {
+  [K in keyof S]-?: S[K] extends false ? K & keyof App : never;
+}[keyof S];
+
+/**
+ * Rows narrow to what the select states: the picked fields, else the record
+ * minus the excluded ones. No `select` returns the full record.
+ */
 export type SelectResult<App, S extends SelectShape<App> | undefined> =
   S extends SelectShape<App>
     ? [TrueKeys<App, S>] extends [never]
-      ? App
+      ? [FalseKeys<App, S>] extends [never]
+        ? App
+        : Omit<App, FalseKeys<App, S>>
       : Pick<App, TrueKeys<App, S>>
     : App;
 
@@ -280,7 +300,10 @@ export class TableClient<App> {
     const all = Object.keys(this.spec.columnByField) as (keyof App & string)[];
     if (!select) return all;
     const picked = all.filter(field => select[field] === true);
-    return picked.length > 0 ? picked : all;
+    if (picked.length > 0) return picked;
+    // Nothing picked: the select either excludes fields or says nothing at all,
+    // and both read what is left.
+    return all.filter(field => select[field] !== false);
   }
 
   private decodeRow<S extends SelectShape<App> | undefined>(

postgres/pg-codegen/__tests__/client.test.ts

@@ -84,6 +84,31 @@ it('treats bare values as equalTo and null as isNull', async () => {
   expect(noEmail.map(u => u.username)).toEqual(['mallory']);
 });
 
+it('excludes a field the binding must not read, and keeps the rest', async () => {
+  const created = await db.users.create({
+    data: { username: 'nadia', email: 'nadia@example.com' },
+    // A column this caller must not carry — the same shape a scope's copy of a
+    // table without the scope key column needs.
+    select: { email: false }
+  });
+  expect(created).toEqual({ id: created.id, username: 'nadia', createdAt: created.createdAt });
+
+  const found = await db.users.findFirstOrThrow({
+    where: { id: created.id },
+    select: { email: false, createdAt: false }
+  });
+  expect(found).toEqual({ id: created.id, username: 'nadia' });
+  // @ts-expect-error an excluded field is absent from the result type, not just the row
+  const _absent: unknown = found.email;
+
+  // A field named `true` is a projection: the exclusions are simply not in it.
+  const projected = await db.users.findFirstOrThrow({
+    where: { id: created.id },
+    select: { username: true, email: false }
+  });
+  expect(projected).toEqual({ username: 'nadia' });
+});
+
 it('combines and/or/not filters', async () => {
   await db.users.create({ data: { username: 'frank' } });
   await db.users.create({ data: { username: 'grace' } });

postgres/pg-codegen/src/emit/templates/client.ts

@@ -33,18 +33,38 @@ export interface TableSpec<App> {
   jsonFields?: readonly string[];
 }
 
-/** Select shape: `{ id: true, name: true }` — same as the GraphQL ORM. */
+/**
+ * Select shape — same as the GraphQL ORM, stated either way round:
+ *
+ * - `{ id: true, name: true }` reads those fields and nothing else;
+ * - `{ databaseId: false }` reads every field except that one, for the field a
+ *   record has in general but this binding's table does not (a scope's copy of
+ *   a table without the scope key column) or that a caller must not carry (a
+ *   secret's id, row bookkeeping).
+ *
+ * Naming a field `true` is a projection and wins outright: the excluded ones
+ * are simply not in it.
+ */
 export type SelectShape<App> = { [K in keyof App]?: boolean };
 
 type TrueKeys<App, S> = {
   [K in keyof S]-?: S[K] extends true ? K & keyof App : never;
 }[keyof S];
 
-/** Rows narrow to the selected fields; no `select` returns the full record. */
+type FalseKeys<App, S> = {
+  [K in keyof S]-?: S[K] extends false ? K & keyof App : never;
+}[keyof S];
+
+/**
+ * Rows narrow to what the select states: the picked fields, else the record
+ * minus the excluded ones. No `select` returns the full record.
+ */
 export type SelectResult<App, S extends SelectShape<App> | undefined> =
   S extends SelectShape<App>
     ? [TrueKeys<App, S>] extends [never]
-      ? App
+      ? [FalseKeys<App, S>] extends [never]
+        ? App
+        : Omit<App, FalseKeys<App, S>>
       : Pick<App, TrueKeys<App, S>>
     : App;
 
@@ -280,7 +300,10 @@ export class TableClient<App> {
     const all = Object.keys(this.spec.columnByField) as (keyof App & string)[];
     if (!select) return all;
     const picked = all.filter(field => select[field] === true);
-    return picked.length > 0 ? picked : all;
+    if (picked.length > 0) return picked;
+    // Nothing picked: the select either excludes fields or says nothing at all,
+    // and both read what is left.
+    return all.filter(field => select[field] !== false);
   }
 
   private decodeRow<S extends SelectShape<App> | undefined>(