Avoid regex template rendering in SQL source

Author: lupuszr

packages/agent/src/generic-sql-source.ts

@@ -752,12 +752,43 @@ function parseQualifiedField(value: string): { dataset?: string; field: string }
 }
 
 function renderTemplate(template: string, row: GenericSqlRow): string {
-  return template.replace(/\{([^}]+)\}/g, (_, field: string) => stringifyRawValue(row[field]));
+  const rendered: string[] = [];
+  let cursor = 0;
+  while (cursor < template.length) {
+    const open = template.indexOf('{', cursor);
+    if (open === -1) {
+      rendered.push(template.slice(cursor));
+      break;
+    }
+    const close = template.indexOf('}', open + 1);
+    if (close === -1) {
+      rendered.push(template.slice(cursor));
+      break;
+    }
+
+    rendered.push(template.slice(cursor, open));
+    const field = template.slice(open + 1, close);
+    rendered.push(field ? stringifyRawValue(row[field]) : template.slice(open, close + 1));
+    cursor = close + 1;
+  }
+  return rendered.join('');
 }
 
 function resolveTemplateArgument(value: string, row: GenericSqlRow): unknown {
-  const exact = /^\{([^}]+)\}$/.exec(value);
-  return exact ? row[exact[1]!] : renderTemplate(value, row);
+  const exact = exactTemplateField(value);
+  return exact ? row[exact] : renderTemplate(value, row);
+}
+
+function exactTemplateField(value: string): string | null {
+  if (!value.startsWith('{') || !value.endsWith('}') || value.length <= 2) {
+    return null;
+  }
+  const close = value.indexOf('}', 1);
+  if (close !== value.length - 1) {
+    return null;
+  }
+  const field = value.slice(1, -1);
+  return field || null;
 }
 
 function stringifyRawValue(value: unknown): string {

packages/agent/test/generic-sql-source.test.ts

@@ -78,6 +78,38 @@ describe('generic SQL source handler', () => {
     }))).rejects.toThrow('dataset orders is missing required columns: quantity');
   });
 
+  it('renders mapping templates without regular expression replacement', async () => {
+    registerGenericSqlConnector(TEST_DIALECT, async (): Promise<GenericSqlClient> => ({
+      async query(_sql, _parameters, dataset) {
+        return rowsByDataset()[dataset] ?? [];
+      },
+    }));
+
+    const result = await genericSqlSourceHandler.prepare(memorySource({
+      ...mapping,
+      entities: [
+        {
+          name: 'order',
+          from: 'orders',
+          id: 'urn:neutral:order:{order_id}',
+          properties: {
+            'https://example.test/composite': 'order-{order_id}-{status}',
+            'https://example.test/emptyBraces': 'literal-{}',
+            'https://example.test/unclosedBrace': 'literal-{status',
+          },
+        },
+      ],
+      relations: [],
+    }));
+
+    const quads = result.assets.flatMap((asset) => asset.quads);
+    expect(quads).toEqual(expect.arrayContaining([
+      quad('urn:neutral:order:A100', 'https://example.test/composite', '"order-A100-ready"'),
+      quad('urn:neutral:order:A100', 'https://example.test/emptyBraces', '"literal-{}"'),
+      quad('urn:neutral:order:A100', 'https://example.test/unclosedBrace', '"literal-{status"'),
+    ]));
+  });
+
   it('selects only asset groups for changed partitions', async () => {
     let rows = rowsByDataset();
     registerGenericSqlConnector(TEST_DIALECT, async (): Promise<GenericSqlClient> => ({