From 7c047cf5f98d2b74ce5920cab9b2c97fe8f90c9f Mon Sep 17 00:00:00 2001
From: Yarchik <spoko.dev@gmail.com>
Date: Thu, 2 Jul 2026 13:16:27 +0100
Subject: [PATCH] fix(number-format): honor min/max-fraction-digits of 0

---
 .../expression/definitions/number_format.ts   |  4 +--
 .../max-fraction-digits-zero/test.json        | 28 +++++++++++++++++++
 2 files changed, 30 insertions(+), 2 deletions(-)
 create mode 100644 test/integration/expression-tests/number-format/max-fraction-digits-zero/test.json

diff --git a/src/style-spec/expression/definitions/number_format.ts b/src/style-spec/expression/definitions/number_format.ts
index b288b94754a..3e8c1234290 100644
--- a/src/style-spec/expression/definitions/number_format.ts
+++ b/src/style-spec/expression/definitions/number_format.ts
@@ -61,13 +61,13 @@ export default class NumberFormat implements Expression {
         }
 
         let minFractionDigits = null;
-        if (options['min-fraction-digits']) {
+        if (options['min-fraction-digits'] !== undefined) {
             minFractionDigits = context.parseObjectValue(options['min-fraction-digits'], 2, 'min-fraction-digits', NumberType);
             if (!minFractionDigits) return null;
         }
 
         let maxFractionDigits = null;
-        if (options['max-fraction-digits']) {
+        if (options['max-fraction-digits'] !== undefined) {
             maxFractionDigits = context.parseObjectValue(options['max-fraction-digits'], 2, 'max-fraction-digits', NumberType);
             if (!maxFractionDigits) return null;
         }
diff --git a/test/integration/expression-tests/number-format/max-fraction-digits-zero/test.json b/test/integration/expression-tests/number-format/max-fraction-digits-zero/test.json
new file mode 100644
index 00000000000..c13ba9ed301
--- /dev/null
+++ b/test/integration/expression-tests/number-format/max-fraction-digits-zero/test.json
@@ -0,0 +1,28 @@
+{
+  "expression": [
+    "number-format",
+    3.7,
+    {
+      "max-fraction-digits": ["get", "max"]
+    }
+  ],
+  "inputs": [
+    [{}, {"properties": {"max": 0}}]
+  ],
+  "expected": {
+    "compiled": {
+      "result": "success",
+      "isFeatureConstant": false,
+      "isZoomConstant": true,
+      "type": "string"
+    },
+    "outputs": ["4"],
+    "serialized": [
+      "number-format",
+      3.7,
+      {
+        "max-fraction-digits": ["number", ["get", "max"]]
+      }
+    ]
+  }
+}