From b08960f7164a24b63374325010bd9bb06ee45e52 Mon Sep 17 00:00:00 2001
From: Katy Bowman <katy.bowman@salesforce.com>
Date: Fri, 11 Sep 2026 12:37:00 -0400
Subject: [PATCH] feat!: remove support for installing legacy plugins

BREAKING CHANGE: removes support for installing legacy plugins
---
 eslint-suppressions.json                | 10 ++--------
 src/plugins.ts                          |  8 --------
 test/integration/install.integration.ts | 19 -------------------
 3 files changed, 2 insertions(+), 35 deletions(-)

diff --git a/eslint-suppressions.json b/eslint-suppressions.json
index e260a691..07222e0e 100644
--- a/eslint-suppressions.json
+++ b/eslint-suppressions.json
@@ -188,14 +188,8 @@
     "@typescript-eslint/no-unsafe-assignment": {
       "count": 1
     },
-    "@typescript-eslint/no-unsafe-call": {
-      "count": 1
-    },
-    "@typescript-eslint/no-unsafe-member-access": {
-      "count": 1
-    },
     "@typescript-eslint/prefer-nullish-coalescing": {
-      "count": 3
+      "count": 2
     },
     "@typescript-eslint/use-unknown-in-catch-callback-variable": {
       "count": 1
@@ -322,4 +316,4 @@
       "count": 1
     }
   }
-}
+}
\ No newline at end of file
diff --git a/src/plugins.ts b/src/plugins.ts
index 75d98a0d..2304c08f 100644
--- a/src/plugins.ts
+++ b/src/plugins.ts
@@ -417,14 +417,6 @@ export default class Plugins {
   private isValidPlugin(p: Config): boolean {
     if (p.valid) return true
 
-    if (
-      this.config.plugins.get('@oclif/plugin-legacy') ||
-      // @ts-expect-error because _base is private
-      p._base.includes('@oclif/plugin-legacy')
-    ) {
-      return true
-    }
-
     throw new Errors.CLIError('plugin is invalid', {
       suggestions: [
         'Plugin failed to install because it does not appear to be a valid CLI plugin.\nIf you are sure it is, contact the CLI developer noting this error.',
diff --git a/test/integration/install.integration.ts b/test/integration/install.integration.ts
index 929a965a..ab02cd07 100644
--- a/test/integration/install.integration.ts
+++ b/test/integration/install.integration.ts
@@ -255,23 +255,4 @@ describe('install/uninstall integration tests', () => {
       expect(result?.some((r) => r.name === plugin)).to.be.false
     })
   })
-
-  describe('legacy plugin', () => {
-    it('should install legacy plugin', async () => {
-      await runCommand('plugins install @oclif/plugin-legacy')
-      await runCommand('plugins install @heroku-cli/plugin-ps-exec --silent')
-      const {result, stdout} = await runCommand<Array<{name: string}>>('plugins')
-      expect(stdout).to.contain('@heroku-cli/plugin-ps-exec')
-      expect(result?.some((r) => r.name === '@heroku-cli/plugin-ps-exec')).to.be.true
-    })
-
-    it('should uninstall legacy plugin', async () => {
-      await runCommand('plugins uninstall @heroku-cli/plugin-ps-exec')
-      await runCommand('plugins uninstall @oclif/plugin-legacy')
-      const {result, stdout} = await runCommand<Array<{name: string}>>('plugins')
-      expect(stdout).to.contain('No plugins installed.')
-      expect(result?.some((r) => r.name === '@heroku-cli/plugin-ps-exec')).to.be.false
-      expect(result?.some((r) => r.name === '@oclif/plugin-legacy')).to.be.false
-    })
-  })
 })