Support precision after SECOND in PostgreSQL interval literal

Author: nene

src/cst/Literal.ts

@@ -156,4 +156,5 @@ export interface IntervalUnit extends BaseNode {
     | "YEAR_MONTH"
     | "YEAR"
   >;
+  precision?: ParenExpr<NumberLiteral>;
 }

src/parser.pegjs

@@ -9078,7 +9078,10 @@ interval_unit_range
   }
 
 interval_unit
-  = kw:interval_unit_kw {
+  = &postgres kw:SECOND precision:(__ paren$number_literal)? {
+    return loc({ type: "interval_unit", unitKw: kw, precision: read(precision) })
+  }
+  / kw:interval_unit_kw {
     return loc({ type: "interval_unit", unitKw: kw })
   }
 

src/showNode/expr.ts

@@ -73,7 +73,7 @@ export const exprMap: FullTransformMap<string, AllExprNodes> = {
   interval_literal: (node) =>
     show([node.intervalKw, node.precision, node.value, node.unit]),
   interval_unit_range: (node) => show([node.fromUnit, node.toKw, node.toUnit]),
-  interval_unit: (node) => show([node.unitKw]),
+  interval_unit: (node) => show([node.unitKw, node.precision]),
 
   // Basic language elements
   identifier: (node) => node.text,

test/literal/interval.test.ts

@@ -146,6 +146,15 @@ describe("INTERVAL literal", () => {
     it("supports INTERVAL with precision argument", () => {
       testExpr(`INTERVAL (4) '8 second'`);
     });
+
+    it("supports INTERVAL with range and precision argument", () => {
+      testExpr(`INTERVAL '8' SECOND (4)`);
+      testExpr(`INTERVAL '8' DAY TO SECOND (2)`);
+    });
+
+    it("parses INTERVAL range with precision as interval_literal", () => {
+      expect(parseExpr(`INTERVAL '8' SECOND (4)`).type).toBe("interval_literal");
+    });
   });
 
   dialect("sqlite", () => {