Add prefer-conditional-expression converter (#1060)

Author: KingDarBoja

src/converters/lintConfigs/rules/ruleConverters.ts

@@ -112,6 +112,7 @@ import { convertOneLine } from "./ruleConverters/one-line";
 import { convertOneVariablePerDeclaration } from "./ruleConverters/one-variable-per-declaration";
 import { convertOnlyArrowFunctions } from "./ruleConverters/only-arrow-functions";
 import { convertOrderedImports } from "./ruleConverters/ordered-imports";
+import { convertPreferConditionalExpression } from "./ruleConverters/prefer-conditional-expression";
 import { convertPreferConst } from "./ruleConverters/prefer-const";
 import { convertPreferForOf } from "./ruleConverters/prefer-for-of";
 import { convertPreferFunctionOverMethod } from "./ruleConverters/prefer-function-over-method";
@@ -374,6 +375,7 @@ export const ruleConverters = new Map([
     ["only-arrow-functions", convertOnlyArrowFunctions],
     ["ordered-imports", convertOrderedImports],
     ["pipe-prefix", convertPipePrefix],
+    ["prefer-conditional-expression", convertPreferConditionalExpression],
     ["prefer-const", convertPreferConst],
     ["prefer-for-of", convertPreferForOf],
     ["prefer-function-over-method", convertPreferFunctionOverMethod],

src/converters/lintConfigs/rules/ruleConverters/prefer-conditional-expression.ts

@@ -0,0 +1,18 @@
+import { RuleConverter } from "../ruleConverter";
+
+export const PREFER_CONDITIONAL_EXPRESSION_NOTICE =
+    "The eslint-plugin-unicorn only supports simple 'if-else' statements.";
+
+export const convertPreferConditionalExpression: RuleConverter = (tslintRule) => {
+    return {
+        rules: [
+            {
+                ...(tslintRule.ruleArguments.length !== 0 && {
+                    notices: [PREFER_CONDITIONAL_EXPRESSION_NOTICE],
+                }),
+                ruleName: "unicorn/prefer-ternary",
+            },
+        ],
+        plugins: ["eslint-plugin-unicorn"],
+    };
+};

src/converters/lintConfigs/rules/ruleConverters/tests/prefer-conditional-expression.test.ts

@@ -0,0 +1,34 @@
+import { convertPreferConditionalExpression, PREFER_CONDITIONAL_EXPRESSION_NOTICE } from "../prefer-conditional-expression";
+
+describe(convertPreferConditionalExpression, () => {
+    test("conversion without arguments", () => {
+        const result = convertPreferConditionalExpression({
+            ruleArguments: [],
+        });
+
+        expect(result).toEqual({
+            rules: [
+                {
+                    ruleName: "unicorn/prefer-ternary",
+                },
+            ],
+            plugins: ["eslint-plugin-unicorn"],
+        });
+    });
+
+    test("conversion with 'check-else-if' argument", () => {
+        const result = convertPreferConditionalExpression({
+            ruleArguments: ['check-else-if'],
+        });
+
+        expect(result).toEqual({
+            rules: [
+                {
+                    notices: [PREFER_CONDITIONAL_EXPRESSION_NOTICE],
+                    ruleName: "unicorn/prefer-ternary",
+                },
+            ],
+            plugins: ["eslint-plugin-unicorn"],
+        });
+    });
+});