From: Josh Kelley <joshkel@gmail.com>
Date: Fri, 18 Apr 2025 11:16:34 +0000 (-0400)
Subject: Require 'this' when calling tick formatters (#12064)
X-Git-Tag: v4.5.0~9
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3361a637052c2e51d5bcf077e727e06a53941a3a;p=thirdparty%2FChart.js.git

Require 'this' when calling tick formatters (#12064)

The `numeric` and `logarithmic` tick formatters require that `this` be provided. That happens automatically if they're used directly as a tick callback but not if they're invoked manually. Failing to pass `this` results in runtime errors similar to the following:

```
TypeError: Cannot read properties of undefined (reading 'chart')
```
---

diff --git a/src/types/index.d.ts b/src/types/index.d.ts
index 898a2c821..69a4cfccb 100644
--- a/src/types/index.d.ts
+++ b/src/types/index.d.ts
@@ -1519,7 +1519,7 @@ export declare const Ticks: {
      * @param ticks the list of ticks being converted
      * @return string representation of the tickValue parameter
      */
-    numeric(tickValue: number, index: number, ticks: { value: number }[]): string;
+    numeric(this: Scale, tickValue: number, index: number, ticks: { value: number }[]): string;
     /**
      * Formatter for logarithmic ticks
      * @param tickValue the value to be formatted
@@ -1527,7 +1527,7 @@ export declare const Ticks: {
      * @param ticks the list of ticks being converted
      * @return string representation of the tickValue parameter
      */
-    logarithmic(tickValue: number, index: number, ticks: { value: number }[]): string;
+    logarithmic(this: Scale, tickValue: number, index: number, ticks: { value: number }[]): string;
   };
 };
 
diff --git a/test/types/ticks/ticks.ts b/test/types/ticks/ticks.ts
new file mode 100644
index 000000000..a5a9e28be
--- /dev/null
+++ b/test/types/ticks/ticks.ts
@@ -0,0 +1,15 @@
+import { Chart, Ticks } from '../../../src/types.js';
+
+// @ts-expect-error The 'this' context... is not assignable to method's 'this' of type 'Scale<CoreScaleOptions>'.
+Ticks.formatters.numeric(0, 0, [{ value: 0 }]);
+
+const chart = new Chart('test', {
+  type: 'line',
+  data: {
+    datasets: [{
+      data: [{ x: 1, y: 1 }]
+    }]
+  },
+});
+
+Ticks.formatters.numeric.call(chart.scales.x, 0, 0, [{ value: 0 }]);