From 8e5043e10e407f7983ede41e7da5f6196151a02e Mon Sep 17 00:00:00 2001
From: Nik Mouzourides <nikolas.mouzourides@gmail.com>
Date: Wed, 2 Oct 2019 17:33:00 +0100
Subject: [PATCH] Implement converter for triple-equals rule #187

---
 src/rules/converters.ts                       |  4 +-
 .../converters/tests/triple-equals.test.ts    | 56 +++++++++++++++++++
 src/rules/converters/triple-equals.ts         | 48 ++++++++++++++++
 3 files changed, 106 insertions(+), 2 deletions(-)
 create mode 100644 src/rules/converters/tests/triple-equals.test.ts
 create mode 100644 src/rules/converters/triple-equals.ts

diff --git a/src/rules/converters.ts b/src/rules/converters.ts
index f1a6289b0..30fdbf5c2 100644
--- a/src/rules/converters.ts
+++ b/src/rules/converters.ts
@@ -99,6 +99,7 @@ import { convertUnifiedSignatures } from "./converters/unified-signatures";
 import { convertUnnecessaryBind } from "./converters/unnecessary-bind";
 import { convertUnnecessaryConstructor } from "./converters/unnecessary-constructor";
 import { convertUseIsnan } from "./converters/use-isnan";
+import { convertTripleEquals } from "./converters/triple-equals";
 
 /**
  * Keys TSLint rule names to their ESLint rule converters.
@@ -205,7 +206,7 @@ export const converters = new Map([
     ["no-octal-literal", convertNoOctalLiteral],
     ["no-regex-spaces", convertNoRegexSpaces],
     ["no-unnecessary-semicolons", convertNoUnnecessarySemicolons],
-
+    ["triple-equals", convertTripleEquals],
     // These converters are all for rules that need more complex option conversions.
     // Some of them will likely need to have notices about changed lint behaviors...
     // If you're willing to take on that work, that'd be great! Please send PRs! 💖
@@ -223,7 +224,6 @@ export const converters = new Map([
     // ["no-void-expression", convertNoVoidExpression], // (no exact equivalent)
     // ["quotemark", convertQuotemark], // quotes
     // ["space-within-parens", convertSpaceWithinParens], // space-in-parens
-    // ["triple-equals", convertTripleEquals], // eqeqeq
     // ["variable-name", convertVariableName], // a bunch of rules...
 
     // tslint-microsoft-contrib rules:
diff --git a/src/rules/converters/tests/triple-equals.test.ts b/src/rules/converters/tests/triple-equals.test.ts
new file mode 100644
index 000000000..ad2940b17
--- /dev/null
+++ b/src/rules/converters/tests/triple-equals.test.ts
@@ -0,0 +1,56 @@
+import { convertTripleEquals } from "../triple-equals";
+
+describe(convertTripleEquals, () => {
+    test("conversion without arguments", () => {
+        const result = convertTripleEquals({
+            ruleArguments: [],
+        });
+
+        expect(result).toEqual({
+            rules: [
+                {
+                    ruleArguments: ["always"],
+                    ruleName: "eqeqeq",
+                    notices: [],
+                },
+            ],
+        });
+    });
+
+    test("conversion with an allow-null-check argument", () => {
+        const result = convertTripleEquals({
+            ruleArguments: ["allow-null-check"],
+        });
+
+        expect(result).toEqual({
+            rules: [
+                {
+                    ruleArguments: ["smart"],
+                    ruleName: "eqeqeq",
+                    notices: [
+                        'Option "smart" allows for comparing two literal values, evaluating the value of typeof and null comparisons.',
+                    ],
+                },
+            ],
+        });
+    });
+
+    test("conversion with an allow-undefined-check argument", () => {
+        const result = convertTripleEquals({
+            ruleArguments: ["allow-undefined-check"],
+        });
+
+        expect(result).toEqual({
+            rules: [
+                {
+                    ruleArguments: ["smart"],
+                    ruleName: "eqeqeq",
+                    notices: [
+                        'Option "allow-undefined-check" is not supported by ESLint. Option "smart" is the closest.',
+                        'Option "smart" allows for comparing two literal values, evaluating the value of typeof and null comparisons.',
+                    ],
+                },
+            ],
+        });
+    });
+});
diff --git a/src/rules/converters/triple-equals.ts b/src/rules/converters/triple-equals.ts
new file mode 100644
index 000000000..26c6975c3
--- /dev/null
+++ b/src/rules/converters/triple-equals.ts
@@ -0,0 +1,48 @@
+import { RuleConverter } from "../converter";
+
+export const convertTripleEquals: RuleConverter = tslintRule => {
+    const getRuleOptions = () => {
+        const smartOptionNotice =
+            'Option "smart" allows for comparing two literal values, evaluating the value of typeof and null comparisons.';
+
+        if (
+            tslintRule.ruleArguments.length !== 0 &&
+            tslintRule.ruleArguments[0] === "allow-null-check"
+        ) {
+            return {
+                arguments: ["smart"],
+                notices: [smartOptionNotice],
+            };
+        }
+
+        if (
+            tslintRule.ruleArguments.length !== 0 &&
+            tslintRule.ruleArguments[0] === "allow-undefined-check"
+        ) {
+            return {
+                arguments: ["smart"],
+                notices: [
+                    'Option "allow-undefined-check" is not supported by ESLint. Option "smart" is the closest.',
+                    smartOptionNotice,
+                ],
+            };
+        }
+
+        return {
+            arguments: ["always"],
+            notices: [],
+        };
+    };
+
+    const options = getRuleOptions();
+
+    return {
+        rules: [
+            {
+                ruleName: "eqeqeq",
+                ruleArguments: options.arguments,
+                notices: options.notices,
+            },
+        ],
+    };
+};