fix(spec): one homeAmount refusal names both faults of a home or rate field

.changeset/28205-home-amount-both-faults.md

@@ -0,0 +1,10 @@
+---
+'@objectstack/spec': patch
+---
+
+fix(spec): a `currencyConfig.homeAmount` home or rate field that lacks `readonly: true` and declares an `expression` is told both faults in one refusal
+
+Clause-②: no
+Metadata-protocol: none
+
+An object whose `homeAmount.field` or `homeAmount.rateField` names a field that lacks `readonly: true` AND declares an `expression` was refused with only the `readonly` fault, so the author added `readonly: true` and met the `expression` fault on the next parse. The one issue at that pointer now names both faults and both remedies: add `readonly: true` to the field and delete its `expression`. The accept set is unchanged; a field with only one of the two faults is told exactly what it was told before.

packages/spec/src/data/currency-config-home-amount.test.ts

@@ -233,6 +233,16 @@ describe('the object judges what `homeAmount` names', () => {
       expect(issues.map((i) => i.path)).toEqual([`${AT}.${key}`]);
       expect(issues[0]!.message).toContain('declares an `expression`');
     });
+
+    it.each(['amount_home', 'amount_rate'] as const)('names both faults in one issue when `%s` has neither mark', (name) => {
+      const issues = objectIssues(invoice({ [name]: { ...BASE_FIELDS[name], readonly: false, expression: 'record.amount' } }));
+      const key = name === 'amount_home' ? 'field' : 'rateField';
+      expect(issues.map((i) => i.path)).toEqual([`${AT}.${key}`]);
+      expect(issues[0]!.code).toBe('custom');
+      expect(issues[0]!.message).toContain('does not declare `readonly: true`');
+      expect(issues[0]!.message).toContain('declares an `expression`');
+      expect(issues[0]!.message).toContain(`Add \`readonly: true\` to \`${name}\` and delete its \`expression\``);
+    });
   });
 
   it('refuses `homeAmount` on a `formula` amount, at `homeAmount`, judging no pointer', () => {

packages/spec/src/data/object.zod.ts

@@ -2034,16 +2034,22 @@ function refuseDishonestHomeAmount(
     // non-system write of it, and no `expression` competes with the engine.
     const refuseUnlessPlatformWritten = (key: 'field' | 'rateField', target: string, what: string): void => {
       const t = map[target];
-      if (t?.readonly === true && t.expression === undefined) return;
+      const writable = t?.readonly !== true;
+      const computed = t?.expression !== undefined;
+      if (!writable && !computed) return;
+      // Both faults on one field are named in one issue, so the author fixes
+      // the field once instead of meeting the second fault on the next parse.
+      const writableFault = 'does not declare `readonly: true`, so a client write could overwrite what the engine stored';
+      const computedFault = 'declares an `expression`, so the engine would store a second, computed value in the same column';
       ctx.addIssue({
         code: 'custom',
         path: [...base, key],
         message: `${at}.${key}\` names \`${target}\`, ${what} only the engine writes, but it `
-          + (t?.readonly === true
-            ? 'declares an `expression`, so the engine would store a second, computed value in the same column. '
-              + `Delete \`expression\` from \`${target}\`.`
-            : 'does not declare `readonly: true`, so a client write could overwrite what the engine stored. '
-              + `Add \`readonly: true\` to \`${target}\`.`),
+          + (writable && computed
+            ? `${writableFault}, and it ${computedFault}. Add \`readonly: true\` to \`${target}\` and delete its \`expression\`.`
+            : writable
+              ? `${writableFault}. Add \`readonly: true\` to \`${target}\`.`
+              : `${computedFault}. Delete \`expression\` from \`${target}\`.`),
       });
     };