feat(codegen): remove underscore from bigint (#7367)

closes #7285
closes #7286

crates/oxc_codegen/src/gen.rs

@@ -1163,12 +1163,14 @@ impl<'a> GenExpr for NumericLiteral<'a> {
 
 impl<'a> Gen for BigIntLiteral<'a> {
     fn gen(&self, p: &mut Codegen, _ctx: Context) {
-        if self.raw.starts_with('-') {
+        let raw = self.raw.as_str().cow_replace('_', "");
+        if raw.starts_with('-') {
             p.print_space_before_operator(Operator::Unary(UnaryOperator::UnaryNegation));
         }
+
         p.print_space_before_identifier();
         p.add_source_mapping(self.span.start);
-        p.print_str(self.raw.as_str());
+        p.print_str(&raw);
     }
 }
 

crates/oxc_codegen/tests/integration/unit.rs

@@ -301,3 +301,68 @@ fn in_expr_in_arrow_function_expression() {
     test("() => 'foo' in bar", "() => \"foo\" in bar;\n");
     test("() => { ('foo' in bar) }", "() => {\n\t\"foo\" in bar;\n};\n");
 }
+
+#[test]
+fn big_int() {
+    test("9007199254740991n;", "9007199254740991n;\n");
+    test("-9007199254740991n;", "-9007199254740991n;\n");
+    test("-90_0719_92547_40991n;", "-9007199254740991n;\n");
+    test("+9007199254740991n;", "+9007199254740991n;\n");
+    test("1000n", "1000n;\n");
+    test("-15n", "-15n;\n");
+
+    test("100_000_000n;", "100000000n;\n");
+    test("10000000000000000n;", "10000000000000000n;\n");
+    test("0n;", "0n;\n");
+    test("+0n;", "+0n;\n");
+    test("-0n;", "-0n;\n");
+
+    test("0x1_0n;", "0x10n;\n");
+    test("0x10n;", "0x10n;\n");
+
+    test("0b1_01n;", "0b101n;\n");
+    test("0b101n;", "0b101n;\n");
+    test("0b101_101n;", "0b101101n;\n");
+    test("0b10_1n", "0b101n;\n");
+
+    test("0o13n;", "0o13n;\n");
+    test("0o7n", "0o7n;\n");
+
+    test("0x2_0n", "0x20n;\n");
+    test("0xfabn", "0xfabn;\n");
+    test("0xaef_en;", "0xaefen;\n");
+    test("0xaefen;", "0xaefen;\n");
+}
+
+#[test]
+#[ignore = "Minify bigint is not implemented."]
+fn big_int_minify() {
+    test_minify("9007199254740991n", "9007199254740991n;");
+    test_minify("-9007199254740991n;", "-9007199254740991n;");
+    test_minify("-90_0719_92547_40991n;", "-9007199254740991n;");
+    test_minify("+9007199254740991n;", "+9007199254740991n;");
+    test_minify("1000n", "1000n;");
+    test_minify("-15n", "-15n;");
+
+    test_minify("100_000_000n;", "100000000n;");
+    test_minify("10000000000000000n;", "0x2386f26fc10000n;");
+    test_minify("0n;", "0n;");
+    test_minify("+0n;", "+0n;");
+    test_minify("-0n;", "-0n;");
+
+    test_minify("0x1_0n;", "16n;");
+    test_minify("0x10n;", "16n;");
+
+    test_minify("0b1_01n;", "5n;");
+    test_minify("0b101n;", "5n;");
+    test_minify("0b101_101n;", "45n;");
+    test_minify("0b10_1n", "5n;");
+
+    test_minify("0o13n;", "11n;");
+    test_minify("0o7n", "7n;");
+
+    test_minify("0x2_0n", "32n;");
+    test_minify("0xfabn", "4011n;");
+    test_minify("0xaef_en;", "44798n;");
+    test_minify("0xaefen;", "44798n;");
+}

crates/oxc_isolated_declarations/tests/snapshots/as-const.snap

@@ -1,6 +1,7 @@
 ---
 source: crates/oxc_isolated_declarations/tests/mod.rs
 input_file: crates/oxc_isolated_declarations/tests/fixtures/as-const.ts
+snapshot_kind: text
 ---
 ```
 ==================== .D.TS ====================
@@ -9,7 +10,7 @@ declare const F: {
 	readonly string: "string";
 	readonly templateLiteral: "templateLiteral";
 	readonly number: 1.23;
-	readonly bigint: -1_2_3n;
+	readonly bigint: -123n;
 	readonly boolean: true;
 	readonly null: null;
 	readonly undefined: undefined;

crates/oxc_isolated_declarations/tests/snapshots/infer-expression.snap

@@ -1,6 +1,7 @@
 ---
 source: crates/oxc_isolated_declarations/tests/mod.rs
 input_file: crates/oxc_isolated_declarations/tests/fixtures/infer-expression.ts
+snapshot_kind: text
 ---
 ```
 ==================== .D.TS ====================
@@ -10,7 +11,7 @@ declare const s: string;
 declare const t: string;
 declare const b: boolean;
 declare let unaryA: number;
-declare const unaryB = -1_2n;
+declare const unaryB = -12n;
 declare const unaryC: unknown;
 declare const unaryD: unknown;
 declare const unaryE: {};