From c4593178ac2eb9d12f05bec2c01463a71567ddaa Mon Sep 17 00:00:00 2001
From: Rob Lourens <roblourens@gmail.com>
Date: Fri, 20 Mar 2026 12:35:44 -0700
Subject: [PATCH] Add eslint rule for telemetry props that override common
 props (#303592)

---
 .../code-no-telemetry-common-property.ts      | 103 ++++++++++++++++++
 eslint.config.js                              |  12 ++
 2 files changed, 115 insertions(+)
 create mode 100644 .eslint-plugin-local/code-no-telemetry-common-property.ts

diff --git a/.eslint-plugin-local/code-no-telemetry-common-property.ts b/.eslint-plugin-local/code-no-telemetry-common-property.ts
new file mode 100644
index 00000000000..2627a09c0a4
--- /dev/null
+++ b/.eslint-plugin-local/code-no-telemetry-common-property.ts
@@ -0,0 +1,103 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as eslint from 'eslint';
+import type * as ESTree from 'estree';
+
+const telemetryMethods = new Set(['publicLog', 'publicLog2', 'publicLogError', 'publicLogError2']);
+
+/**
+ * Common telemetry property names that are automatically added to every event.
+ * Telemetry events must not set these because they would collide with / be
+ * overwritten by the common properties that the telemetry pipeline injects.
+ *
+ * Collected from:
+ *   - src/vs/platform/telemetry/common/commonProperties.ts  (resolveCommonProperties)
+ *   - src/vs/workbench/services/telemetry/common/workbenchCommonProperties.ts
+ *   - src/vs/workbench/services/telemetry/browser/workbenchCommonProperties.ts
+ */
+const commonTelemetryProperties = new Set([
+	'common.machineid',
+	'common.sqmid',
+	'common.devdeviceid',
+	'sessionid',
+	'commithash',
+	'version',
+	'common.releasedate',
+	'common.platformversion',
+	'common.platform',
+	'common.nodeplatform',
+	'common.nodearch',
+	'common.product',
+	'common.msftinternal',
+	'timestamp',
+	'common.timesincesessionstart',
+	'common.sequence',
+	'common.snap',
+	'common.platformdetail',
+	'common.version.shell',
+	'common.version.renderer',
+	'common.firstsessiondate',
+	'common.lastsessiondate',
+	'common.isnewsession',
+	'common.remoteauthority',
+	'common.cli',
+	'common.useragent',
+	'common.istouchdevice',
+]);
+
+export default new class NoTelemetryCommonProperty implements eslint.Rule.RuleModule {
+
+	readonly meta: eslint.Rule.RuleMetaData = {
+		messages: {
+			noCommonProperty: 'Telemetry events must not contain the common property "{{name}}". Common properties are automatically added by the telemetry pipeline and will be dropped.',
+		},
+		schema: false,
+	};
+
+	create(context: eslint.Rule.RuleContext): eslint.Rule.RuleListener {
+
+		/**
+		 * Check whether any property key in an object expression is a reserved common telemetry property.
+		 */
+		function checkObjectForCommonProperties(node: ESTree.ObjectExpression) {
+			for (const prop of node.properties) {
+				if (prop.type === 'Property') {
+					let name: string | undefined;
+					if (prop.key.type === 'Identifier') {
+						name = prop.key.name;
+					} else if (prop.key.type === 'Literal' && typeof prop.key.value === 'string') {
+						name = prop.key.value;
+					}
+					if (name && commonTelemetryProperties.has(name.toLowerCase())) {
+						context.report({
+							node: prop.key,
+							messageId: 'noCommonProperty',
+							data: { name },
+						});
+					}
+				}
+			}
+		}
+
+		return {
+			['CallExpression[callee.property.type="Identifier"]'](node: ESTree.CallExpression) {
+				const callee = node.callee;
+				if (callee.type !== 'MemberExpression') {
+					return;
+				}
+				const prop = callee.property;
+				if (prop.type !== 'Identifier' || !telemetryMethods.has(prop.name)) {
+					return;
+				}
+				// The data argument is the second argument for publicLog/publicLog2/publicLogError/publicLogError2
+				const dataArg = node.arguments[1];
+				if (dataArg && dataArg.type === 'ObjectExpression') {
+					checkObjectForCommonProperties(dataArg);
+				}
+			},
+		};
+	}
+};
diff --git a/eslint.config.js b/eslint.config.js
index ff390f5c4b2..681a41a26d4 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -183,6 +183,18 @@ export default tseslint.config(
 			]
 		}
 	},
+	// Disallow common telemetry properties in event data
+	{
+		files: [
+			'src/**/*.ts',
+		],
+		plugins: {
+			'local': pluginLocal,
+		},
+		rules: {
+			'local/code-no-telemetry-common-property': 'warn',
+		}
+	},
 	// Disallow 'in' operator except in type predicates
 	{
 		files: [