From 61be53cf0296f418eb3d2d3fbe86d98c0d996a76 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Tue, 16 Apr 2024 08:10:29 +0200
Subject: [PATCH] fix: correctly get and set top level `contentType` property
 (#625)

---
 CHANGELOG.md |  1 +
 index.d.ts   |  6 +++---
 index.js     | 17 ++++++++++++-----
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bfdc0edc..3f947b5a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 
 - Add `Registry.PROMETHEUS_CONTENT_TYPE` and `Registry.OPENMETRICS_CONTENT_TYPE` constants to the TypeScript types
+- Correctly read and set `contentType` top level export
 
 ### Added
 
diff --git a/index.d.ts b/index.d.ts
index 61439abc..99d12677 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -81,7 +81,7 @@ export class Registry<RegistryContentType = PrometheusContentType> {
 	/**
 	 * Gets the Content-Type of the metrics for use in the response headers.
 	 */
-	contentType: RegistryContentType;
+	readonly contentType: RegistryContentType;
 
 	/**
 	 * Set the content type of a registry. Used to change between Prometheus and
@@ -114,8 +114,8 @@ export type Collector = () => void;
 export const register: Registry;
 
 /**
- * HTTP Content-Type for metrics response headers, defaults to Prometheus text
- * format.
+ * HTTP Content-Type for metrics response headers for the default registry,
+ * defaults to Prometheus text format.
  */
 export const contentType: RegistryContentType;
 
diff --git a/index.js b/index.js
index 7f6e167a..f78105fc 100644
--- a/index.js
+++ b/index.js
@@ -7,11 +7,18 @@
 
 exports.register = require('./lib/registry').globalRegistry;
 exports.Registry = require('./lib/registry');
-exports.contentType = require('./lib/registry').globalRegistry.contentType;
-exports.prometheusContentType =
-	require('./lib/registry').PROMETHEUS_CONTENT_TYPE;
-exports.openMetricsContentType =
-	require('./lib/registry').OPENMETRICS_CONTENT_TYPE;
+Object.defineProperty(exports, 'contentType', {
+	configurable: false,
+	enumerable: true,
+	get() {
+		return exports.register.contentType;
+	},
+	set(value) {
+		exports.register.setContentType(value);
+	},
+});
+exports.prometheusContentType = exports.Registry.PROMETHEUS_CONTENT_TYPE;
+exports.openMetricsContentType = exports.Registry.OPENMETRICS_CONTENT_TYPE;
 exports.validateMetricName = require('./lib/validation').validateMetricName;
 
 exports.Counter = require('./lib/counter');