From b757bd8d6910dc1b75f014eaec1f2d36fa38cf4d Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Fri, 24 Apr 2020 08:45:16 +0000
Subject: [PATCH 01/13] Fix: clone config data before validation (fixes #12592)

---
 lib/cli-engine/config-array-factory.js |  4 +++-
 tests/lib/rules/camelcase.js           | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index 997a7e15318..74a8319217a 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -43,6 +43,7 @@ const fs = require("fs");
 const path = require("path");
 const importFresh = require("import-fresh");
 const stripComments = require("strip-json-comments");
+const lodash = require("lodash");
 const { validateConfigSchema } = require("../shared/config-validator");
 const naming = require("../shared/naming");
 const ModuleResolver = require("../shared/relative-module-resolver");
@@ -593,8 +594,9 @@ class ConfigArrayFactory {
             ? path.resolve(cwd, providedFilePath)
             : "";
         const name = providedName || (filePath && path.relative(cwd, filePath));
+        const clonedConfig = lodash.cloneDeep(configData);
 
-        validateConfigSchema(configData, name || filePath);
+        validateConfigSchema(clonedConfig, name || filePath);
 
         return this._normalizeObjectConfigData(configData, filePath, name);
     }
diff --git a/tests/lib/rules/camelcase.js b/tests/lib/rules/camelcase.js
index 21f280adb35..80dbe183c9d 100644
--- a/tests/lib/rules/camelcase.js
+++ b/tests/lib/rules/camelcase.js
@@ -225,6 +225,10 @@ ruleTester.run("camelcase", rule, {
             code: "foo = { [computedBar]: 0 };",
             options: [{ ignoreDestructuring: true }],
             parserOptions: { ecmaVersion: 6 }
+        },
+        {
+            code: "var obj = { mem_var: 1 };",
+            options: [{ properties: "never" }]
         }
     ],
     invalid: [
@@ -736,6 +740,25 @@ ruleTester.run("camelcase", rule, {
                     type: "Identifier"
                 }
             ]
+        },
+        {
+            code: "const {mem_var = 1} = obh",
+            options: [{ ignoreDestructuring: false }],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [{
+                messageId: "notCamelCase",
+                data: { name: "mem_var" },
+                type: "Identifier"
+            }]
+        },
+        {
+            code: "var obj = { mem_var: 1 };",
+            options: [{}],
+            errors: [{
+                messageId: "notCamelCase",
+                data: { name: "mem_var" },
+                type: "Identifier"
+            }]
         }
     ]
 });

From ef60d4cae04c66f6eeb2445dc28b81160c9522cc Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Wed, 29 Apr 2020 06:44:53 +0000
Subject: [PATCH 02/13] Chore: added test  and cloning before validation

---
 lib/cli-engine/config-array-factory.js        |  4 +--
 lib/shared/config-validator.js                |  4 ++-
 .../config-file/cloned-config/eslintConfig.js |  4 +++
 .../config-file/cloned-config/index.js        |  1 +
 .../config-file/cloned-config/inlineText.js   |  3 +++
 tests/lib/cli.js                              | 26 +++++++++++++++++++
 6 files changed, 38 insertions(+), 4 deletions(-)
 create mode 100644 tests/fixtures/config-file/cloned-config/eslintConfig.js
 create mode 100644 tests/fixtures/config-file/cloned-config/index.js
 create mode 100644 tests/fixtures/config-file/cloned-config/inlineText.js

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index 48e03a08e10..67211f6e9f4 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -43,7 +43,6 @@ const fs = require("fs");
 const path = require("path");
 const importFresh = require("import-fresh");
 const stripComments = require("strip-json-comments");
-const lodash = require("lodash");
 const { validateConfigSchema } = require("../shared/config-validator");
 const naming = require("../shared/naming");
 const ModuleResolver = require("../shared/relative-module-resolver");
@@ -624,9 +623,8 @@ class ConfigArrayFactory {
      * @private
      */
     _normalizeConfigData(configData, ctx) {
-        const clonedConfig = lodash.cloneDeep(configData);
 
-        validateConfigSchema(clonedConfig, ctx.name || ctx.filePath);
+        validateConfigSchema(configData, ctx.name || ctx.filePath);
         return this._normalizeObjectConfigData(configData, ctx);
     }
 
diff --git a/lib/shared/config-validator.js b/lib/shared/config-validator.js
index 458bd2a802b..9f6bb509b1f 100644
--- a/lib/shared/config-validator.js
+++ b/lib/shared/config-validator.js
@@ -15,6 +15,7 @@ const
     BuiltInEnvironments = require("../../conf/environments"),
     BuiltInRules = require("../rules"),
     ConfigOps = require("./config-ops"),
+    _ = require("lodash"),
     { emitDeprecationWarning } = require("./deprecation-warnings");
 
 const ajv = require("./ajv")();
@@ -183,8 +184,9 @@ function validateRules(
 
     Object.keys(rulesConfig).forEach(id => {
         const rule = getAdditionalRule(id) || BuiltInRules.get(id) || null;
+        const clonedRulesConfigForId = _.cloneDeep(rulesConfig[id]);
 
-        validateRuleOptions(rule, id, rulesConfig[id], source);
+        validateRuleOptions(rule, id, clonedRulesConfigForId, source);
     });
 }
 
diff --git a/tests/fixtures/config-file/cloned-config/eslintConfig.js b/tests/fixtures/config-file/cloned-config/eslintConfig.js
new file mode 100644
index 00000000000..8602e60b0fd
--- /dev/null
+++ b/tests/fixtures/config-file/cloned-config/eslintConfig.js
@@ -0,0 +1,4 @@
+let errorConfig = ["error", {}];
+module.exports = {
+    rules: { camelcase: errorConfig, "default-case": errorConfig }
+};
diff --git a/tests/fixtures/config-file/cloned-config/index.js b/tests/fixtures/config-file/cloned-config/index.js
new file mode 100644
index 00000000000..b792f78cad3
--- /dev/null
+++ b/tests/fixtures/config-file/cloned-config/index.js
@@ -0,0 +1 @@
+var someValue  = "bar";
diff --git a/tests/fixtures/config-file/cloned-config/inlineText.js b/tests/fixtures/config-file/cloned-config/inlineText.js
new file mode 100644
index 00000000000..e000713abaf
--- /dev/null
+++ b/tests/fixtures/config-file/cloned-config/inlineText.js
@@ -0,0 +1,3 @@
+/*eslint default-case: ["error", {}]*/
+/*eslint camelcase: ["error", {}]*/
+var someValue  = "bar";
diff --git a/tests/lib/cli.js b/tests/lib/cli.js
index 6af3b5c838e..ee082e50615 100644
--- a/tests/lib/cli.js
+++ b/tests/lib/cli.js
@@ -185,6 +185,7 @@ describe("cli", () => {
         });
     });
 
+
     describe("when given a config with environment set to Node.js", () => {
         it("should execute without any errors", () => {
             const configPath = getFixturePath("configurations", "env-node.json");
@@ -1192,4 +1193,29 @@ describe("cli", () => {
         });
     });
 
+    describe("testing the cloned config", () => {
+        describe("config file and input file", () => {
+            it("should execute without any errors", () => {
+                const configPath = getFixturePath("config-file", "cloned-config", "eslintConfig.js");
+                const filePath = getFixturePath("config-file", "cloned-config", "index.js");
+                const code = `--config ${configPath} ${filePath}`;
+
+                const exit = cli.execute(code);
+
+                assert.strictEqual(exit, 0);
+            });
+        });
+
+        describe("inline config and input file", () => {
+            it("should execute without any errors", () => {
+                const filePath = getFixturePath("config-file", "cloned-config", "inlineText.js");
+                const code = `${filePath}`;
+
+                const exit = cli.execute(code);
+
+                assert.strictEqual(exit, 0);
+            });
+        });
+    });
+
 });

From ca2e7068140d7b1111f7efcafd648339cd1517d5 Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Wed, 29 Apr 2020 08:05:03 +0000
Subject: [PATCH 03/13] Chore: test fix

---
 tests/lib/cli.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/lib/cli.js b/tests/lib/cli.js
index 093d6168c51..e1df3ec75a1 100644
--- a/tests/lib/cli.js
+++ b/tests/lib/cli.js
@@ -1163,23 +1163,23 @@ describe("cli", () => {
 
     describe("testing the cloned config", () => {
         describe("config file and input file", () => {
-            it("should execute without any errors", () => {
+            it("should execute without any errors", async () => {
                 const configPath = getFixturePath("config-file", "cloned-config", "eslintConfig.js");
                 const filePath = getFixturePath("config-file", "cloned-config", "index.js");
                 const code = `--config ${configPath} ${filePath}`;
 
-                const exit = cli.execute(code);
+                const exit = await cli.execute(code);
 
                 assert.strictEqual(exit, 0);
             });
         });
 
         describe("inline config and input file", () => {
-            it("should execute without any errors", () => {
+            it("should execute without any errors", async () => {
                 const filePath = getFixturePath("config-file", "cloned-config", "inlineText.js");
                 const code = `${filePath}`;
 
-                const exit = cli.execute(code);
+                const exit = await cli.execute(code);
 
                 assert.strictEqual(exit, 0);
             });

From df673322060b5b6e169ad89eed9aea5a0fd24192 Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Wed, 29 Apr 2020 08:46:15 +0000
Subject: [PATCH 04/13] Chore: rules tests fixes

---
 tests/lib/rules/computed-property-spacing.js |  4 ++--
 tests/lib/rules/use-isnan.js                 | 10 ----------
 2 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/tests/lib/rules/computed-property-spacing.js b/tests/lib/rules/computed-property-spacing.js
index b0ecef6eb81..3514abc120f 100644
--- a/tests/lib/rules/computed-property-spacing.js
+++ b/tests/lib/rules/computed-property-spacing.js
@@ -782,7 +782,7 @@ ruleTester.run("computed-property-spacing", rule, {
         {
             code: "A = class { [ a ](){} get [ b ](){} set [ c ](foo){} static [ d ](){} static get [ e ](){} static set [ f ](bar){} }",
             output: "A = class { [a](){} get [b](){} set [c](foo){} static [d](){} static get [e](){} static set [f](bar){} }",
-            options: ["never", {}],
+            options: ["never"],
             parserOptions: { ecmaVersion: 6 },
             errors: [
                 {
@@ -1040,7 +1040,7 @@ ruleTester.run("computed-property-spacing", rule, {
         {
             code: "class A { [a](){} get [b](){} set [c](foo){} static [d](){} static get [e](){} static set [f](bar){} }",
             output: "class A { [ a ](){} get [ b ](){} set [ c ](foo){} static [ d ](){} static get [ e ](){} static set [ f ](bar){} }",
-            options: ["always", {}],
+            options: ["always"],
             parserOptions: { ecmaVersion: 6 },
             errors: [
                 {
diff --git a/tests/lib/rules/use-isnan.js b/tests/lib/rules/use-isnan.js
index aa1b1746fcd..0f0ba8678fc 100644
--- a/tests/lib/rules/use-isnan.js
+++ b/tests/lib/rules/use-isnan.js
@@ -280,16 +280,6 @@ ruleTester.run("use-isnan", rule, {
             code: "switch(foo) { case NaN: break; }",
             errors: [{ messageId: "caseNaN", type: "SwitchCase", column: 15 }]
         },
-        {
-            code: "switch(NaN) { case foo: break; }",
-            options: [{}],
-            errors: [{ messageId: "switchNaN", type: "SwitchStatement", column: 1 }]
-        },
-        {
-            code: "switch(foo) { case NaN: break; }",
-            options: [{}],
-            errors: [{ messageId: "caseNaN", type: "SwitchCase", column: 15 }]
-        },
         {
             code: "switch(NaN) {}",
             options: [{ enforceForSwitchCase: true }],

From 2260565f3a129ab31cb6c70dd44b580338b6bc1f Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Thu, 7 May 2020 07:00:03 +0000
Subject: [PATCH 05/13] Update: cloning config using json parse and stringify

---
 lib/cli-engine/config-array-factory.js       |  4 +++-
 lib/shared/config-validator.js               |  4 +---
 tests/lib/rules/computed-property-spacing.js |  4 ++--
 tests/lib/rules/use-isnan.js                 | 10 ++++++++++
 4 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index 96af54af93b..e5bf870d150 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -625,7 +625,9 @@ class ConfigArrayFactory {
     _normalizeConfigData(configData, ctx) {
 
         validateConfigSchema(configData, ctx.name || ctx.filePath);
-        return this._normalizeObjectConfigData(configData, ctx);
+        const clonedConfig = JSON.parse(JSON.stringify(configData));
+
+        return this._normalizeObjectConfigData(clonedConfig, ctx);
     }
 
     /**
diff --git a/lib/shared/config-validator.js b/lib/shared/config-validator.js
index 9f6bb509b1f..458bd2a802b 100644
--- a/lib/shared/config-validator.js
+++ b/lib/shared/config-validator.js
@@ -15,7 +15,6 @@ const
     BuiltInEnvironments = require("../../conf/environments"),
     BuiltInRules = require("../rules"),
     ConfigOps = require("./config-ops"),
-    _ = require("lodash"),
     { emitDeprecationWarning } = require("./deprecation-warnings");
 
 const ajv = require("./ajv")();
@@ -184,9 +183,8 @@ function validateRules(
 
     Object.keys(rulesConfig).forEach(id => {
         const rule = getAdditionalRule(id) || BuiltInRules.get(id) || null;
-        const clonedRulesConfigForId = _.cloneDeep(rulesConfig[id]);
 
-        validateRuleOptions(rule, id, clonedRulesConfigForId, source);
+        validateRuleOptions(rule, id, rulesConfig[id], source);
     });
 }
 
diff --git a/tests/lib/rules/computed-property-spacing.js b/tests/lib/rules/computed-property-spacing.js
index 3514abc120f..b7055461573 100644
--- a/tests/lib/rules/computed-property-spacing.js
+++ b/tests/lib/rules/computed-property-spacing.js
@@ -782,7 +782,7 @@ ruleTester.run("computed-property-spacing", rule, {
         {
             code: "A = class { [ a ](){} get [ b ](){} set [ c ](foo){} static [ d ](){} static get [ e ](){} static set [ f ](bar){} }",
             output: "A = class { [a](){} get [b](){} set [c](foo){} static [d](){} static get [e](){} static set [f](bar){} }",
-            options: ["never"],
+            options: ["never", {}],
             parserOptions: { ecmaVersion: 6 },
             errors: [
                 {
@@ -924,7 +924,7 @@ ruleTester.run("computed-property-spacing", rule, {
         {
             code: "A = class { [a](){} get [b](){} set [c](foo){} static [d](){} static get [e](){} static set [f](bar){} }",
             output: "A = class { [ a ](){} get [ b ](){} set [ c ](foo){} static [ d ](){} static get [ e ](){} static set [ f ](bar){} }",
-            options: ["always"],
+            options: ["always", {}],
             parserOptions: { ecmaVersion: 6 },
             errors: [
                 {
diff --git a/tests/lib/rules/use-isnan.js b/tests/lib/rules/use-isnan.js
index 0f0ba8678fc..aa1b1746fcd 100644
--- a/tests/lib/rules/use-isnan.js
+++ b/tests/lib/rules/use-isnan.js
@@ -280,6 +280,16 @@ ruleTester.run("use-isnan", rule, {
             code: "switch(foo) { case NaN: break; }",
             errors: [{ messageId: "caseNaN", type: "SwitchCase", column: 15 }]
         },
+        {
+            code: "switch(NaN) { case foo: break; }",
+            options: [{}],
+            errors: [{ messageId: "switchNaN", type: "SwitchStatement", column: 1 }]
+        },
+        {
+            code: "switch(foo) { case NaN: break; }",
+            options: [{}],
+            errors: [{ messageId: "caseNaN", type: "SwitchCase", column: 15 }]
+        },
         {
             code: "switch(NaN) {}",
             options: [{ enforceForSwitchCase: true }],

From 024f2681bdec4667a380e5cb14f92108ce0a99e3 Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Thu, 7 May 2020 07:07:19 +0000
Subject: [PATCH 06/13] Update: changed test description

---
 tests/lib/cli.js                             | 12 ++++++------
 tests/lib/rules/computed-property-spacing.js |  4 ++--
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/tests/lib/cli.js b/tests/lib/cli.js
index e1df3ec75a1..c97c5495bee 100644
--- a/tests/lib/cli.js
+++ b/tests/lib/cli.js
@@ -1163,23 +1163,23 @@ describe("cli", () => {
 
     describe("testing the cloned config", () => {
         describe("config file and input file", () => {
-            it("should execute without any errors", async () => {
+            it("should not modify original configuration object", async () => {
                 const configPath = getFixturePath("config-file", "cloned-config", "eslintConfig.js");
                 const filePath = getFixturePath("config-file", "cloned-config", "index.js");
-                const code = `--config ${configPath} ${filePath}`;
+                const args = `--config ${configPath} ${filePath}`;
 
-                const exit = await cli.execute(code);
+                const exit = await cli.execute(args);
 
                 assert.strictEqual(exit, 0);
             });
         });
 
         describe("inline config and input file", () => {
-            it("should execute without any errors", async () => {
+            it("should not modify original configuration object", async () => {
                 const filePath = getFixturePath("config-file", "cloned-config", "inlineText.js");
-                const code = `${filePath}`;
+                const args = `${filePath}`;
 
-                const exit = await cli.execute(code);
+                const exit = await cli.execute(args);
 
                 assert.strictEqual(exit, 0);
             });
diff --git a/tests/lib/rules/computed-property-spacing.js b/tests/lib/rules/computed-property-spacing.js
index b7055461573..b0ecef6eb81 100644
--- a/tests/lib/rules/computed-property-spacing.js
+++ b/tests/lib/rules/computed-property-spacing.js
@@ -924,7 +924,7 @@ ruleTester.run("computed-property-spacing", rule, {
         {
             code: "A = class { [a](){} get [b](){} set [c](foo){} static [d](){} static get [e](){} static set [f](bar){} }",
             output: "A = class { [ a ](){} get [ b ](){} set [ c ](foo){} static [ d ](){} static get [ e ](){} static set [ f ](bar){} }",
-            options: ["always", {}],
+            options: ["always"],
             parserOptions: { ecmaVersion: 6 },
             errors: [
                 {
@@ -1040,7 +1040,7 @@ ruleTester.run("computed-property-spacing", rule, {
         {
             code: "class A { [a](){} get [b](){} set [c](foo){} static [d](){} static get [e](){} static set [f](bar){} }",
             output: "class A { [ a ](){} get [ b ](){} set [ c ](foo){} static [ d ](){} static get [ e ](){} static set [ f ](bar){} }",
-            options: ["always"],
+            options: ["always", {}],
             parserOptions: { ecmaVersion: 6 },
             errors: [
                 {

From 0374e39ebf115f1691207cad40a125405cf61701 Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Thu, 7 May 2020 10:04:25 +0000
Subject: [PATCH 07/13] Chore: removed unnecessary tests

---
 tests/lib/rules/camelcase.js | 23 -----------------------
 1 file changed, 23 deletions(-)

diff --git a/tests/lib/rules/camelcase.js b/tests/lib/rules/camelcase.js
index 0bceea81aae..1e3eecc2110 100644
--- a/tests/lib/rules/camelcase.js
+++ b/tests/lib/rules/camelcase.js
@@ -226,10 +226,6 @@ ruleTester.run("camelcase", rule, {
             options: [{ ignoreDestructuring: true }],
             parserOptions: { ecmaVersion: 6 }
         },
-        {
-            code: "var obj = { mem_var: 1 };",
-            options: [{ properties: "never" }]
-        },
         {
             code: "({ a: obj.fo_o } = bar);",
             options: [{ allow: ["fo_o"] }],
@@ -794,25 +790,6 @@ ruleTester.run("camelcase", rule, {
                 }
             ]
         },
-        {
-            code: "const {mem_var = 1} = obh",
-            options: [{ ignoreDestructuring: false }],
-            parserOptions: { ecmaVersion: 6 },
-            errors: [{
-                messageId: "notCamelCase",
-                data: { name: "mem_var" },
-                type: "Identifier"
-            }]
-        },
-        {
-            code: "var obj = { mem_var: 1 };",
-            options: [{}],
-            errors: [{
-                messageId: "notCamelCase",
-                data: { name: "mem_var" },
-                type: "Identifier"
-            }]
-        },
         {
             code: "({ a: obj.fo_o } = bar);",
             parserOptions: { ecmaVersion: 6 },

From 79a1a1915a721de75ec43e357cef7883a08c43e8 Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Fri, 15 May 2020 14:28:40 +0000
Subject: [PATCH 08/13] Update: changed clone logic

---
 lib/cli-engine/config-array-factory.js        | 32 ++++++++++++++++++-
 .../cloned-config/eslintConfigFail.js         | 13 ++++++++
 tests/lib/cli.js                              | 15 +++++++++
 3 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 tests/fixtures/config-file/cloned-config/eslintConfigFail.js

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index e5bf870d150..bf68120daad 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -625,7 +625,37 @@ class ConfigArrayFactory {
     _normalizeConfigData(configData, ctx) {
 
         validateConfigSchema(configData, ctx.name || ctx.filePath);
-        const clonedConfig = JSON.parse(JSON.stringify(configData));
+
+        /**
+         * Function to clone a object ref https://stackoverflow.com/a/1042676/9339537
+         * @param {Object} from object which needs to be cloned
+         * @returns {Object} returns the cloned object
+         */
+        function clone(from) {
+
+            if (from === null || typeof from !== "object") {
+                return from;
+            }
+            if (from.constructor !== Object && from.constructor !== Array) {
+                return from;
+            }
+            if (from.constructor === Date || from.constructor === RegExp || from.constructor === Function ||
+        from.constructor === String || from.constructor === Number || from.constructor === Boolean) {
+                return new from.constructor(from);
+            }
+
+            const clonedResult = new from.constructor();
+
+            for (const name in from) {
+
+                if (typeof clonedResult[name] === "undefined") {
+                    clonedResult[name] = clone(from[name]);
+                }
+            }
+
+            return clonedResult;
+        }
+        const clonedConfig = clone(configData);
 
         return this._normalizeObjectConfigData(clonedConfig, ctx);
     }
diff --git a/tests/fixtures/config-file/cloned-config/eslintConfigFail.js b/tests/fixtures/config-file/cloned-config/eslintConfigFail.js
new file mode 100644
index 00000000000..b8702c6ffb8
--- /dev/null
+++ b/tests/fixtures/config-file/cloned-config/eslintConfigFail.js
@@ -0,0 +1,13 @@
+let errorConfig = ["error", {}];
+module.exports = {
+    rules: {
+        camelcase: errorConfig,
+        "default-case": errorConfig ,
+        "camelcase" : [
+            'error',
+            {
+                "ignoreDestructuring": new Date().getUTCFullYear // returns a function
+            }
+        ]
+    }
+};
diff --git a/tests/lib/cli.js b/tests/lib/cli.js
index c97c5495bee..5488b896224 100644
--- a/tests/lib/cli.js
+++ b/tests/lib/cli.js
@@ -1174,6 +1174,21 @@ describe("cli", () => {
             });
         });
 
+        describe("config file and input file", () => {
+            it("should exit with 1 as camelcase has wrong property type", async () => {
+                const configPath = getFixturePath("config-file", "cloned-config", "eslintConfigFail.js");
+                const filePath = getFixturePath("config-file", "cloned-config", "index.js");
+                const args = `--config ${configPath} ${filePath}`;
+
+                try {
+                    await cli.execute(args);
+                } catch (error) {
+                    assert.strictEqual(/Configuration for rule "camelcase" is invalid:/u.test(error), true);
+                }
+
+            });
+        });
+
         describe("inline config and input file", () => {
             it("should not modify original configuration object", async () => {
                 const filePath = getFixturePath("config-file", "cloned-config", "inlineText.js");

From a20065d3ee0294fc83b4bff90b78365b805e3ec7 Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Thu, 21 May 2020 15:19:12 +0000
Subject: [PATCH 09/13] Update: using lodash.cloneDeepWith for cloning

---
 lib/cli-engine/config-array-factory.js | 37 +++++++++++---------------
 1 file changed, 15 insertions(+), 22 deletions(-)

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index bf68120daad..db74a7925e7 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -43,6 +43,7 @@ const fs = require("fs");
 const path = require("path");
 const importFresh = require("import-fresh");
 const stripComments = require("strip-json-comments");
+const lodash = require("lodash");
 const { validateConfigSchema } = require("../shared/config-validator");
 const naming = require("../shared/naming");
 const ModuleResolver = require("../shared/relative-module-resolver");
@@ -627,35 +628,27 @@ class ConfigArrayFactory {
         validateConfigSchema(configData, ctx.name || ctx.filePath);
 
         /**
-         * Function to clone a object ref https://stackoverflow.com/a/1042676/9339537
-         * @param {Object} from object which needs to be cloned
+         * Customizer for lodash.cloneDeepWith
          * @returns {Object} returns the cloned object
          */
-        function clone(from) {
+        function getCustomizer() {
+            let root = true;
 
-            if (from === null || typeof from !== "object") {
-                return from;
-            }
-            if (from.constructor !== Object && from.constructor !== Array) {
-                return from;
-            }
-            if (from.constructor === Date || from.constructor === RegExp || from.constructor === Function ||
-        from.constructor === String || from.constructor === Number || from.constructor === Boolean) {
-                return new from.constructor(from);
-            }
-
-            const clonedResult = new from.constructor();
+            return function customizer(value) {
+                if (!root && typeof value === "object" && value !== null) {
 
-            for (const name in from) {
-
-                if (typeof clonedResult[name] === "undefined") {
-                    clonedResult[name] = clone(from[name]);
+                    // start new lodash.cloneDeepWith
+                    return lodash.cloneDeepWith(value, getCustomizer());
                 }
-            }
 
-            return clonedResult;
+                root = false;
+
+                // return `undefined` for the default lodash.cloneDeepWith behavior
+                return void 0;
+            };
         }
-        const clonedConfig = clone(configData);
+
+        const clonedConfig = lodash.cloneDeepWith(configData, getCustomizer());
 
         return this._normalizeObjectConfigData(clonedConfig, ctx);
     }

From 1453116c5e31338d747e0770a6032412538e2ede Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Sat, 23 May 2020 09:51:07 +0000
Subject: [PATCH 10/13] Update: handling circular ref cases

---
 lib/cli-engine/config-array-factory.js        | 48 ++++++++++++++-----
 .../cloned-config/circularRefEslintConfig.js  | 15 ++++++
 tests/lib/cli.js                              | 15 ++++++
 3 files changed, 67 insertions(+), 11 deletions(-)
 create mode 100644 tests/fixtures/config-file/cloned-config/circularRefEslintConfig.js

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index db74a7925e7..b3eba8bfa44 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -628,27 +628,53 @@ class ConfigArrayFactory {
         validateConfigSchema(configData, ctx.name || ctx.filePath);
 
         /**
-         * Customizer for lodash.cloneDeepWith
+         * Cloning function using lodash.cloneDeepWith
+         * @param {Object} val Object which needs to be cloned
          * @returns {Object} returns the cloned object
          */
-        function getCustomizer() {
-            let root = true;
+        function cloneDeep(val) {
+            const seenObjects = new Set();
+            let forceDefault = false;
+
+            /**
+             * Customizer for lodash.cloneDeepWith
+             * @param {Object} value value that needs to be clone with custom logic
+             * @returns {Object} returns the cloned object
+             */
+            function customizer(value) {
+                if (typeof value === "object" && value !== null) {
+                    if (forceDefault) {
+                        forceDefault = false;
+                    } else {
+                        if (seenObjects.has(value)) {
+                            throw new Error("Cannot clone circular structure");
+                        }
 
-            return function customizer(value) {
-                if (!root && typeof value === "object" && value !== null) {
+                        seenObjects.add(value);
+                        forceDefault = true;
+                        const clonedValue = lodash.cloneDeepWith(value, customizer);
 
-                    // start new lodash.cloneDeepWith
-                    return lodash.cloneDeepWith(value, getCustomizer());
-                }
+                        seenObjects.delete(value);
 
-                root = false;
+                        return clonedValue;
+                    }
+                }
 
                 // return `undefined` for the default lodash.cloneDeepWith behavior
                 return void 0;
-            };
+            }
+
+            return lodash.cloneDeepWith(val, customizer);
         }
 
-        const clonedConfig = lodash.cloneDeepWith(configData, getCustomizer());
+        let clonedConfig = configData;
+
+        try {
+            clonedConfig = cloneDeep(clonedConfig);
+        } catch (error) {
+            debug("Failed to clone config object as it noticed some circular reference. Using the original config");
+            clonedConfig = configData;
+        }
 
         return this._normalizeObjectConfigData(clonedConfig, ctx);
     }
diff --git a/tests/fixtures/config-file/cloned-config/circularRefEslintConfig.js b/tests/fixtures/config-file/cloned-config/circularRefEslintConfig.js
new file mode 100644
index 00000000000..cc9fcdbcc7c
--- /dev/null
+++ b/tests/fixtures/config-file/cloned-config/circularRefEslintConfig.js
@@ -0,0 +1,15 @@
+let errorConfig = ["error", {}];
+
+class CircularRef {
+  constructor() {
+    this.self = this;
+  }
+}
+
+module.exports = {
+  settings: {
+    sharedData: new CircularRef()
+  },
+
+  rules: { camelcase: errorConfig, "default-case": errorConfig }
+};
diff --git a/tests/lib/cli.js b/tests/lib/cli.js
index 5488b896224..946db48f573 100644
--- a/tests/lib/cli.js
+++ b/tests/lib/cli.js
@@ -1199,6 +1199,21 @@ describe("cli", () => {
                 assert.strictEqual(exit, 0);
             });
         });
+
+        describe("handling circular reference while cloning", () => {
+            it("should handle circular ref", async () => {
+                const configPath = getFixturePath("config-file", "cloned-config", "circularRefEslintConfig.js");
+                const filePath = getFixturePath("config-file", "cloned-config", "index.js");
+                const args = `--config ${configPath} ${filePath}`;
+
+                try {
+                    await cli.execute(args);
+                } catch (error) {
+                    assert.instanceOf(error, Error);
+                    assert.strictEqual(/Configuration for rule "default-case" is invalid/iu.test(error), true);
+                }
+            });
+        });
     });
 
 });

From 949b3ee720e216ccdc0d23adb06bd5972a52f19a Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Sat, 13 Jun 2020 16:24:48 +0000
Subject: [PATCH 11/13] Update: using JSON method for cloning logic

---
 lib/cli-engine/config-array-factory.js | 50 +-------------------------
 tests/lib/cli.js                       | 14 --------
 2 files changed, 1 insertion(+), 63 deletions(-)

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index b3eba8bfa44..5e56aa5edf9 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -43,7 +43,6 @@ const fs = require("fs");
 const path = require("path");
 const importFresh = require("import-fresh");
 const stripComments = require("strip-json-comments");
-const lodash = require("lodash");
 const { validateConfigSchema } = require("../shared/config-validator");
 const naming = require("../shared/naming");
 const ModuleResolver = require("../shared/relative-module-resolver");
@@ -627,54 +626,7 @@ class ConfigArrayFactory {
 
         validateConfigSchema(configData, ctx.name || ctx.filePath);
 
-        /**
-         * Cloning function using lodash.cloneDeepWith
-         * @param {Object} val Object which needs to be cloned
-         * @returns {Object} returns the cloned object
-         */
-        function cloneDeep(val) {
-            const seenObjects = new Set();
-            let forceDefault = false;
-
-            /**
-             * Customizer for lodash.cloneDeepWith
-             * @param {Object} value value that needs to be clone with custom logic
-             * @returns {Object} returns the cloned object
-             */
-            function customizer(value) {
-                if (typeof value === "object" && value !== null) {
-                    if (forceDefault) {
-                        forceDefault = false;
-                    } else {
-                        if (seenObjects.has(value)) {
-                            throw new Error("Cannot clone circular structure");
-                        }
-
-                        seenObjects.add(value);
-                        forceDefault = true;
-                        const clonedValue = lodash.cloneDeepWith(value, customizer);
-
-                        seenObjects.delete(value);
-
-                        return clonedValue;
-                    }
-                }
-
-                // return `undefined` for the default lodash.cloneDeepWith behavior
-                return void 0;
-            }
-
-            return lodash.cloneDeepWith(val, customizer);
-        }
-
-        let clonedConfig = configData;
-
-        try {
-            clonedConfig = cloneDeep(clonedConfig);
-        } catch (error) {
-            debug("Failed to clone config object as it noticed some circular reference. Using the original config");
-            clonedConfig = configData;
-        }
+        const clonedConfig = JSON.parse(JSON.stringify(configData));
 
         return this._normalizeObjectConfigData(clonedConfig, ctx);
     }
diff --git a/tests/lib/cli.js b/tests/lib/cli.js
index 946db48f573..a44f51afb59 100644
--- a/tests/lib/cli.js
+++ b/tests/lib/cli.js
@@ -1200,20 +1200,6 @@ describe("cli", () => {
             });
         });
 
-        describe("handling circular reference while cloning", () => {
-            it("should handle circular ref", async () => {
-                const configPath = getFixturePath("config-file", "cloned-config", "circularRefEslintConfig.js");
-                const filePath = getFixturePath("config-file", "cloned-config", "index.js");
-                const args = `--config ${configPath} ${filePath}`;
-
-                try {
-                    await cli.execute(args);
-                } catch (error) {
-                    assert.instanceOf(error, Error);
-                    assert.strictEqual(/Configuration for rule "default-case" is invalid/iu.test(error), true);
-                }
-            });
-        });
     });
 
 });

From a786d386507c44b34b52b1cf83069247c22613bf Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Sun, 14 Jun 2020 09:52:15 +0000
Subject: [PATCH 12/13] Update: moved clone logic to normalieObjectConfigData

---
 lib/cli-engine/config-array-factory.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index 5e56aa5edf9..8714fe0c517 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -626,9 +626,7 @@ class ConfigArrayFactory {
 
         validateConfigSchema(configData, ctx.name || ctx.filePath);
 
-        const clonedConfig = JSON.parse(JSON.stringify(configData));
-
-        return this._normalizeObjectConfigData(clonedConfig, ctx);
+        return this._normalizeObjectConfigData(configData, ctx);
     }
 
     /**
@@ -701,6 +699,8 @@ class ConfigArrayFactory {
             ctx.matchBasePath
         );
 
+        const clonedRulesConfig = rules && JSON.parse(JSON.stringify((rules)));
+
         // Flatten `extends`.
         for (const extendName of extendList.filter(Boolean)) {
             yield* this._loadExtends(extendName, ctx);
@@ -735,7 +735,7 @@ class ConfigArrayFactory {
             processor,
             reportUnusedDisableDirectives,
             root,
-            rules,
+            rules: clonedRulesConfig,
             settings
         };
 

From b030e8320ac637525c5de202680f2350996ae821 Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Sun, 14 Jun 2020 12:40:16 +0000
Subject: [PATCH 13/13] Chore: added comments for cloning reason

---
 lib/cli-engine/config-array-factory.js | 27 ++++++++++++++++++++++++--
 tests/lib/cli.js                       | 13 +++++++++++++
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/lib/cli-engine/config-array-factory.js b/lib/cli-engine/config-array-factory.js
index 8714fe0c517..ccb7b7d5490 100644
--- a/lib/cli-engine/config-array-factory.js
+++ b/lib/cli-engine/config-array-factory.js
@@ -623,9 +623,7 @@ class ConfigArrayFactory {
      * @private
      */
     _normalizeConfigData(configData, ctx) {
-
         validateConfigSchema(configData, ctx.name || ctx.filePath);
-
         return this._normalizeObjectConfigData(configData, ctx);
     }
 
@@ -699,6 +697,31 @@ class ConfigArrayFactory {
             ctx.matchBasePath
         );
 
+        /**
+         * Cloning the rule's config as we are setting `useDefaults` to true`
+         * which mutates the config with its default value if present. And when we
+         * refer to a same variable for config for different rules, that referred variable will
+         * be mutated and it will be used for both.
+         *
+         * Example:
+         *
+         * const commonRuleConfig  = ['error', {}];
+         *
+         * Now if we use this variable as a config for rules like this
+         *
+         * {
+         *      rules: {
+         *          "a" : commonRuleConfig,
+         *          "b" : commonRuleConfig,
+         *      }
+         * }
+         *
+         * And if these rules have default values in their schema, their
+         * config will be mutated with default values, the mutated `commonRuleConfig` will be used for `b` as well and it probably
+         * throw schema voilation errors.
+         *
+         * Refer https://github.com/eslint/eslint/issues/12592
+         */
         const clonedRulesConfig = rules && JSON.parse(JSON.stringify((rules)));
 
         // Flatten `extends`.
diff --git a/tests/lib/cli.js b/tests/lib/cli.js
index a44f51afb59..afb225f1f7c 100644
--- a/tests/lib/cli.js
+++ b/tests/lib/cli.js
@@ -1202,4 +1202,17 @@ describe("cli", () => {
 
     });
 
+    describe("handling circular reference while cloning", () => {
+        it("should handle circular ref", async () => {
+            const configPath = getFixturePath("config-file", "cloned-config", "circularRefEslintConfig.js");
+            const filePath = getFixturePath("config-file", "cloned-config", "index.js");
+            const args = `--config ${configPath} ${filePath}`;
+
+            try {
+                await cli.execute(args);
+            } catch (error) {
+                assert.instanceOf(error, Error);
+            }
+        });
+    });
 });