Fixed an import reporting its own fault as the row's error

A row's custom field values are validated before its transaction opens, so
by the time they are written there is nothing left in them that can be
refused. A write that fails there is the database saying no to us, not to
the publisher, and it was being handled as though it were the publisher's:
the driver's message, query text and all, went into the error file they open
next to their spreadsheet, and nobody who could act on it was told. The
failure still fails the row, because half a member is worse than none, but
the publisher now reads a sentence about what did not save and the original
goes to the error tracker, where a lock timeout or a constraint is something
someone can go and look at.

ref https://linear.app/ghost/issue/BER-3872

Author: rob-ghost

ghost/core/core/server/services/members/import-export/import/importer.ts

@@ -182,6 +182,7 @@ const messages = {
   giftCannotCombineWithImportTier: 'Cannot specify both gift_id and import_tier.',
   giftCannotCombineWithComplimentary: 'Cannot specify both gift_id and complimentary_plan.',
   giftReassignFailed: 'Failed to reassign gift to member.',
+  customFieldWriteFailed: 'Failed to save the custom field values for this member.',
 };
 
 // Columns whose presence makes a row slow to import (they reach out to Stripe), so
@@ -581,7 +582,16 @@ class MembersCSVImporter {
         }
 
         // On the row's transaction, so the values commit or roll back with the member.
-        await this._customFields.applyWrite(member.id, customFieldPlan, trx);
+        try {
+          await this._customFields.applyWrite(member.id, customFieldPlan, trx);
+        } catch (writeError) {
+          // planWrite passed every value before the transaction opened, so a failure
+          // here is ours and not the row's. Operators get the original, which a driver
+          // will have written a query into; the publisher gets a sentence instead, in a
+          // file they open next to a spreadsheet.
+          this._report(writeError);
+          throw new errors.DataImportError({ message: tpl(messages.customFieldWriteFailed) });
+        }
 
         await trx.commit();
         imported += 1;

ghost/core/test/unit/server/services/members/import-export/import/error-handling.test.ts

@@ -243,6 +243,23 @@ describe('members import error handling', function () {
       assert.deepEqual(h.reported, []);
     });
 
+    // The one row failure whose fault is known: the values were validated before the
+    // transaction opened, so nothing left in them can be what threw here.
+    it('keeps a fault of its own out of the error file and sends it to operators', async function () {
+      const h = harness([row('first@example.com')]);
+      const fault = new Error('ER_LOCK_WAIT_TIMEOUT: update `members_custom_field_values` set ...');
+      h.deps.customFields.applyWrite = async () => {
+        throw fault;
+      };
+
+      await h.run();
+
+      assert.equal(h.onlyReport(), fault);
+      const attached = h.onlyEmail().attachments[0].content;
+      assert.match(attached, /Failed to save the custom field values for this member/);
+      assert.doesNotMatch(attached, /ER_LOCK_WAIT_TIMEOUT|members_custom_field_values/);
+    });
+
     it('reports an import where every row failed as unsuccessful', async function () {
       const h = harness();
       h.deps.members.create = async () => {