util: support BigInt in util.format

`util.format` and `console.log` now support BigInt via the existing format specifiers `%i` and `%d`. PR-URL: #22097 Reviewed-By: Roman Reiss <me@silverwind.io> Reviewed-By: James M Snell <jasnell@gmail.com>
nodejs · Oct 17, 2018 · 5029fd0 · 5029fd0
1 parent e0f996c
commit 5029fd0
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Showing 3 changed files with 50 additions and 4 deletions.
diff --git a/doc/api/util.md b/doc/api/util.md
@@ -202,8 +202,8 @@ Each placeholder token is replaced with the converted value from the
 corresponding argument. Supported placeholders are:
 
 * `%s` - `String`.
-* `%d` - `Number` (integer or floating point value).
-* `%i` - Integer.
+* `%d` - `Number` (integer or floating point value) or `BigInt`.
+* `%i` - Integer or `BigInt`.
 * `%f` - Floating point value.
 * `%j` - JSON. Replaced with the string `'[Circular]'` if the argument
 contains circular references.

diff --git a/lib/util.js b/lib/util.js
@@ -102,7 +102,13 @@ function formatWithOptions(inspectOptions, f) {
             tempStr = tryStringify(arguments[a++]);
             break;
           case 100: // 'd'
-            tempStr = `${Number(arguments[a++])}`;
+            const tempNum = arguments[a++];
+            // eslint-disable-next-line valid-typeof
+            if (typeof tempNum === 'bigint') {
+              tempStr = `${tempNum}n`;
+            } else {
+              tempStr = `${Number(tempNum)}`;
+            }
             break;
           case 79: // 'O'
             tempStr = inspect(arguments[a++], inspectOptions);
@@ -117,7 +123,13 @@ function formatWithOptions(inspectOptions, f) {
             break;
           }
           case 105: // 'i'
-            tempStr = `${parseInt(arguments[a++])}`;
+            const tempInteger = arguments[a++];
+            // eslint-disable-next-line valid-typeof
+            if (typeof tempInteger === 'bigint') {
+              tempStr = `${tempInteger}n`;
+            } else {
+              tempStr = `${parseInt(tempInteger)}`;
+            }
             break;
           case 102: // 'f'
             tempStr = `${parseFloat(arguments[a++])}`;

diff --git a/test/parallel/test-util-format.js b/test/parallel/test-util-format.js
@@ -68,6 +68,18 @@ assert.strictEqual(util.format('%d', -0.5), '-0.5');
 assert.strictEqual(util.format('%d', ''), '0');
 assert.strictEqual(util.format('%d %d', 42, 43), '42 43');
 assert.strictEqual(util.format('%d %d', 42), '42 %d');
+assert.strictEqual(
+  util.format('%d', 1180591620717411303424),
+  '1.1805916207174113e+21'
+);
+assert.strictEqual(
+  util.format('%d', 1180591620717411303424n),
+  '1180591620717411303424n'
+);
+assert.strictEqual(
+  util.format('%d %d', 1180591620717411303424n, 12345678901234567890123n),
+  '1180591620717411303424n 12345678901234567890123n'
+);
 
 // Integer format specifier
 assert.strictEqual(util.format('%i'), '%i');
@@ -80,6 +92,28 @@ assert.strictEqual(util.format('%i', -0.5), '0');
 assert.strictEqual(util.format('%i', ''), 'NaN');
 assert.strictEqual(util.format('%i %i', 42, 43), '42 43');
 assert.strictEqual(util.format('%i %i', 42), '42 %i');
+assert.strictEqual(
+  util.format('%i', 1180591620717411303424),
+  '1'
+);
+assert.strictEqual(
+  util.format('%i', 1180591620717411303424n),
+  '1180591620717411303424n'
+);
+assert.strictEqual(
+  util.format('%i %i', 1180591620717411303424n, 12345678901234567890123n),
+  '1180591620717411303424n 12345678901234567890123n'
+);
+
+assert.strictEqual(
+  util.format('%d %i', 1180591620717411303424n, 12345678901234567890123n),
+  '1180591620717411303424n 12345678901234567890123n'
+);
+
+assert.strictEqual(
+  util.format('%i %d', 1180591620717411303424n, 12345678901234567890123n),
+  '1180591620717411303424n 12345678901234567890123n'
+);
 
 // Float format specifier
 assert.strictEqual(util.format('%f'), '%f');