fix: strip quotes and uppercase EXTRACT field name in deparser

The EXTRACT SQL syntax handler was passing the A_Const sval value
directly, which gets single-quoted by QuoteUtils.formatEString().
This produced EXTRACT('epoch' FROM x) instead of the correct
EXTRACT(EPOCH FROM x).

Strip surrounding quotes and uppercase the field name to match
PostgreSQL's expected EXTRACT syntax.

Ref: constructive-io/constructive-db#748

Author: pyramation

packages/deparser/__tests__/misc/extract.test.ts

@@ -0,0 +1,36 @@
+import { expectParseDeparse } from '../../test-utils';
+
+it('should deparse EXTRACT(EPOCH FROM ...) correctly', async () => {
+    const sql = `SELECT EXTRACT(EPOCH FROM now())`;
+    const result = await expectParseDeparse(sql);
+    expect(result).toContain('EXTRACT(EPOCH FROM');
+    expect(result).not.toContain("'epoch'");
+});
+
+it('should deparse EXTRACT(YEAR FROM ...) correctly', async () => {
+    const sql = `SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40')`;
+    const result = await expectParseDeparse(sql);
+    expect(result).toContain('EXTRACT(YEAR FROM');
+    expect(result).not.toContain("'year'");
+});
+
+it('should deparse EXTRACT(EPOCH FROM ...) with pretty option', async () => {
+    const sql = `SELECT EXTRACT(EPOCH FROM now())`;
+    const result = await expectParseDeparse(sql, { pretty: true });
+    expect(result).toContain('EXTRACT(EPOCH FROM');
+    expect(result).not.toContain("'epoch'");
+});
+
+it('should deparse EXTRACT(CENTURY FROM ...) correctly', async () => {
+    const sql = `SELECT EXTRACT(CENTURY FROM DATE '2001-01-01')`;
+    const result = await expectParseDeparse(sql);
+    expect(result).toContain('EXTRACT(CENTURY FROM');
+    expect(result).not.toContain("'century'");
+});
+
+it('should deparse EXTRACT(MILLENNIUM FROM ...) correctly', async () => {
+    const sql = `SELECT EXTRACT(MILLENNIUM FROM DATE '2001-01-01')`;
+    const result = await expectParseDeparse(sql);
+    expect(result).toContain('EXTRACT(MILLENNIUM FROM');
+    expect(result).not.toContain("'millennium'");
+});

packages/deparser/src/deparser.ts

@@ -1446,8 +1446,13 @@ export class Deparser implements DeparserVisitor {
 
     // Handle EXTRACT function with SQL syntax
     if (node.funcformat === 'COERCE_SQL_SYNTAX' && name === 'pg_catalog.extract' && args.length >= 2) {
-      const field = this.visit(args[0], context);
+      let field = this.visit(args[0], context);
       const source = this.visit(args[1], context);
+      // EXTRACT requires an unquoted uppercase keyword (EPOCH, YEAR, etc.)
+      // but A_Const sval deparsing wraps it in single quotes — strip and uppercase
+      if (field.startsWith("'") && field.endsWith("'")) {
+        field = field.slice(1, -1).toUpperCase();
+      }
       return `EXTRACT(${field} FROM ${source})`;
     }