From c65a1391be15bbcf3ae293b1c53686703883d546 Mon Sep 17 00:00:00 2001
From: Armano <armano2@users.noreply.github.com>
Date: Sun, 28 Feb 2021 20:11:01 +0100
Subject: [PATCH] fix(eslint-plugin): [unbound-method] allow `super`
 expressions in `this` assignments (#3010)

---
 .../eslint-plugin/src/rules/unbound-method.ts |  9 ++-
 .../tests/rules/unbound-method.test.ts        | 59 +++++++++++++++++++
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/packages/eslint-plugin/src/rules/unbound-method.ts b/packages/eslint-plugin/src/rules/unbound-method.ts
index 407d04c11ec..2ec66bc2aa3 100644
--- a/packages/eslint-plugin/src/rules/unbound-method.ts
+++ b/packages/eslint-plugin/src/rules/unbound-method.ts
@@ -305,7 +305,14 @@ function isSafeUse(node: TSESTree.Node): boolean {
       return ['instanceof', '==', '!=', '===', '!=='].includes(parent.operator);
 
     case AST_NODE_TYPES.AssignmentExpression:
-      return parent.operator === '=' && node === parent.left;
+      return (
+        parent.operator === '=' &&
+        (node === parent.left ||
+          (node.type === AST_NODE_TYPES.MemberExpression &&
+            node.object.type === AST_NODE_TYPES.Super &&
+            parent.left.type === AST_NODE_TYPES.MemberExpression &&
+            parent.left.object.type === AST_NODE_TYPES.ThisExpression))
+      );
 
     case AST_NODE_TYPES.ChainExpression:
     case AST_NODE_TYPES.TSNonNullExpression:
diff --git a/packages/eslint-plugin/tests/rules/unbound-method.test.ts b/packages/eslint-plugin/tests/rules/unbound-method.test.ts
index 83f3b93524c..911206b1f21 100644
--- a/packages/eslint-plugin/tests/rules/unbound-method.test.ts
+++ b/packages/eslint-plugin/tests/rules/unbound-method.test.ts
@@ -265,6 +265,22 @@ class Foo {
 }
 const { bound } = new Foo();
     `,
+    // https://github.com/typescript-eslint/typescript-eslint/issues/1866
+    `
+class BaseClass {
+  x: number = 42;
+  logThis() {}
+}
+class OtherClass extends BaseClass {
+  superLogThis: any;
+  constructor() {
+    super();
+    this.superLogThis = super.logThis;
+  }
+}
+const oc = new OtherClass();
+oc.superLogThis();
+    `,
   ],
   invalid: [
     {
@@ -529,5 +545,48 @@ const { log } = console;
         },
       ],
     },
+    // https://github.com/typescript-eslint/typescript-eslint/issues/1866
+    {
+      code: `
+class BaseClass {
+  logThis() {}
+}
+class OtherClass extends BaseClass {
+  constructor() {
+    super();
+    const x = super.logThis;
+  }
+}
+      `,
+      errors: [
+        {
+          line: 8,
+          column: 15,
+          messageId: 'unbound',
+        },
+      ],
+    },
+    // https://github.com/typescript-eslint/typescript-eslint/issues/1866
+    {
+      code: `
+class BaseClass {
+  logThis() {}
+}
+class OtherClass extends BaseClass {
+  constructor() {
+    super();
+    let x;
+    x = super.logThis;
+  }
+}
+      `,
+      errors: [
+        {
+          line: 9,
+          column: 9,
+          messageId: 'unbound',
+        },
+      ],
+    },
   ],
 });