Implement sqlLiteralCase option for TRUE/FALSE/NULL

Author: nene

src/options.ts

@@ -41,7 +41,8 @@ export const options: SupportOptions = {
     type: "choice",
     category: "SQL",
     default: "upper",
-    description: "Enforces upper/lower case for SQL literals",
+    description:
+      "Enforces upper/lower case for SQL literals (TRUE, FALSE, NULL)",
     choices: [
       {
         value: "preserve",

src/syntax/expr.ts

@@ -23,6 +23,7 @@ import {
   isCompoundSelectStmt,
 } from "../node_utils";
 import { isString, last } from "../utils";
+import { AllPrettierOptions } from "src/options";
 
 export const exprMap: CstToDocMap<AllExprNodes> = {
   list_expr: (print, node, path) => {
@@ -169,13 +170,15 @@ export const exprMap: CstToDocMap<AllExprNodes> = {
   /** cst-ignore: value */
   number_literal: (print) => print("text"),
   /** cst-ignore: value */
-  boolean_literal: (print) => print("valueKw"),
+  boolean_literal: (print, node, path, options) =>
+    printLiteral(node.valueKw, options),
   /** cst-ignore: value */
   string_literal: (print) => print("text"),
   /** cst-ignore: value */
   blob_literal: (print) => print("text"),
   /** cst-ignore: value */
-  null_literal: (print) => print("nullKw"),
+  null_literal: (print, node, path, options) =>
+    printLiteral(node.nullKw, options),
   numeric_literal: (print) => print.spaced(["numericKw", "string"]),
   bignumeric_literal: (print) => print.spaced(["bignumericKw", "string"]),
   date_literal: (print) => print.spaced(["dateKw", "string"]),
@@ -191,4 +194,15 @@ export const exprMap: CstToDocMap<AllExprNodes> = {
   parameter: (print) => print("text"),
 };
 
+const printLiteral = <T>(node: Keyword, options: AllPrettierOptions<T>) => {
+  switch (options.sqlLiteralCase) {
+    case "preserve":
+      return node.text;
+    case "upper":
+      return node.text.toUpperCase();
+    case "lower":
+      return node.text.toLowerCase();
+  }
+};
+
 const isBooleanOp = ({ name }: Keyword) => name === "AND" || name === "OR";

test/options/literalCase.test.ts

@@ -0,0 +1,40 @@
+import dedent from "dedent-js";
+import { pretty } from "../test_utils";
+
+describe("sqlLiteralCase option", () => {
+  it(`defaults to uppercasing of all literals`, async () => {
+    expect(await pretty(`SELECT true, false, null`)).toBe(dedent`
+      SELECT TRUE, FALSE, NULL
+    `);
+  });
+
+  it(`sqlKeywordCase: "preserve" keeps keywords case as-is`, async () => {
+    expect(
+      await pretty(`SELECT true, False, NULL`, {
+        sqlLiteralCase: "preserve",
+      }),
+    ).toBe(dedent`
+      SELECT true, False, NULL
+    `);
+  });
+
+  it(`sqlLiteralCase: "upper" converts keywords to uppercase`, async () => {
+    expect(
+      await pretty(`SELECT true, False, NULL`, {
+        sqlLiteralCase: "upper",
+      }),
+    ).toBe(dedent`
+      SELECT TRUE, FALSE, NULL
+    `);
+  });
+
+  it(`sqlLiteralCase: "lower" converts keywords to lowercase`, async () => {
+    expect(
+      await pretty(`SELECT true, False, NULL`, {
+        sqlLiteralCase: "lower",
+      }),
+    ).toBe(dedent`
+      SELECT true, false, null
+    `);
+  });
+});