fix(sqlite): honor selected-table reply budgets (#4216)

src/sqlite/SqliteDatabaseInspection.ts

@@ -255,14 +255,29 @@ const readSchema = (
     );
   let selectedTable: SelectedTableFacts | undefined;
   const metadata = new Map<string, z.output<typeof tableRow>>();
-  // Names bound the minimum eventual schema output while metadata is collected.
-  // The full schema objects below account for them in the actual reply budget.
+  const selectedKey =
+    selectedName === undefined ? undefined : sqliteIdentifierKey(selectedName);
+  const unresolvedVirtualTables: { name: string; prefix: string }[] = [];
+  // Names bound eventual output only when the whole catalog is requested.
+  // Selected scope retains one table and at most one possible shadow parent;
+  // unrelated names are examined without retaining them or charging the reply.
   const metadataBudget = new OutputBudget();
   for (const raw of db.prepare("PRAGMA main.table_list").iterate()) {
     const value = tableRow.parse(raw);
-    if (value.schema === "main") {
+    if (value.schema !== "main") continue;
+    if (selectedName === undefined) {
       metadataBudget.retain(value.name);
       metadata.set(value.name, value);
+    } else if (value.name === selectedName) {
+      metadata.set(value.name, value);
+    }
+    if (value.type === "virtual" && value.ncol === 0) {
+      const prefix = sqliteIdentifierKey(`${value.name}_`);
+      if (
+        selectedKey === undefined ||
+        (unresolvedVirtualTables.length === 0 && selectedKey.startsWith(prefix))
+      )
+        unresolvedVirtualTables.push({ name: value.name, prefix });
     }
   }
   // A trigger stores its target as written in CREATE TRIGGER, which SQLite
@@ -278,12 +293,6 @@ const readSchema = (
     );
     return foldedNames.get(sqliteIdentifierKey(written)) ?? written;
   };
-  const unresolvedVirtualTables = [...metadata.values()]
-    .filter((value) => value.type === "virtual" && value.ncol === 0)
-    .map((value) => ({
-      name: value.name,
-      prefix: sqliteIdentifierKey(`${value.name}_`),
-    }));
   const shadowParentOf = (
     name: string,
     listed: z.output<typeof tableRow>,

tests/boundary/sqlite/sqliteDatabaseInspection.test.ts

@@ -235,6 +235,53 @@ it("counts schema names once when enforcing the complete reply budget", async ()
   );
 });
 
+it("keeps unrelated catalog names outside the selected-table reply budget", async () => {
+  const path = await createDatabase(
+    "CREATE TABLE selected(value TEXT); INSERT INTO selected VALUES ('retained');",
+  );
+  const producer = new DatabaseSync(path);
+  try {
+    producer.exec("BEGIN");
+    for (let index = 0; index < 60; index++) {
+      const name = `unrelated_${index}_${"x".repeat(300 * 1024)}`;
+      producer.exec(`CREATE TABLE "${name}" (value TEXT)`);
+    }
+    producer.exec("COMMIT");
+  } finally {
+    producer.close();
+  }
+  const selected = inspectSqliteDatabaseSnapshot(path, {
+    path,
+    table: "selected",
+  });
+  expect(selected.schema).toMatchObject({
+    scope: "selected_table",
+    completeness: "complete",
+    tables: [{ name: "selected" }],
+    indexes: [],
+    views: [],
+    triggers: [],
+  });
+  expect(selected.schema.tables).toHaveLength(1);
+  expect(selected.rows).toMatchObject({
+    returned_rows: 1,
+    values: [[{ type: "text", value: "retained" }]],
+  });
+  expect(() =>
+    inspectSqliteDatabaseSnapshot(path, { path, table: "absent" }),
+  ).toThrowError(
+    expect.objectContaining({
+      reason: "selection",
+      message:
+        "Selected ordinary table does not exist with that exact name: absent",
+    }),
+  );
+  for (const schema_scope of ["inventory", "database"] as const)
+    expect(() =>
+      inspectSqliteDatabaseSnapshot(path, { path, schema_scope }),
+    ).toThrowError(expect.objectContaining({ reason: "output-limit" }));
+});
+
 it("rejects malformed schema bytes instead of returning replacement text", async () => {
   const path = await createDatabase(
     "CREATE TABLE records(value TEXT /*schema-marker*/)",