Draft "NoImplicitFunctionReturnType"

Author: ILIYANGERMANOV

src/main/kotlin/com/github/ivy/explicit/IvyExplicitRuleSetProvider.kt

@@ -3,6 +3,7 @@ package com.github.ivy.explicit
 import com.github.ivy.explicit.rule.DataClassDefaultValuesRule
 import com.github.ivy.explicit.rule.DataClassFunctionsRule
 import com.github.ivy.explicit.rule.DataClassTypedIDsRule
+import com.github.ivy.explicit.rule.NoImplicitFunctionReturnTypeRule
 import io.gitlab.arturbosch.detekt.api.Config
 import io.gitlab.arturbosch.detekt.api.RuleSet
 import io.gitlab.arturbosch.detekt.api.RuleSetProvider
@@ -16,7 +17,8 @@ class IvyExplicitRuleSetProvider : RuleSetProvider {
             listOf(
                 DataClassFunctionsRule(config),
                 DataClassDefaultValuesRule(config),
-                DataClassTypedIDsRule(config)
+                DataClassTypedIDsRule(config),
+                NoImplicitFunctionReturnTypeRule(config),
             ),
         )
     }

src/main/kotlin/com/github/ivy/explicit/rule/NoImplicitFunctionReturnTypeRule.kt

@@ -0,0 +1,29 @@
+package com.github.ivy.explicit.rule
+
+import io.gitlab.arturbosch.detekt.api.*
+import org.jetbrains.kotlin.psi.KtNamedFunction
+
+class NoImplicitFunctionReturnTypeRule(config: Config) : Rule(config) {
+
+    override val issue = Issue(
+        "NoImplicitFunctionReturnType",
+        Severity.Warning,
+        "Functions and class methods should declare their return types explicitly to improve code readability and maintainability.",
+        Debt.FIVE_MINS
+    )
+
+    override fun visitNamedFunction(function: KtNamedFunction) {
+        super.visitNamedFunction(function)
+        // Check if the function has an explicit return type
+        if (function.typeReference == null && !function.hasBlockBody() && !function.isLocal) {
+            report(
+                CodeSmell(
+                    issue,
+                    Entity.from(function),
+                    "The function '${function.name}' should declare an explicit return type."
+                )
+            )
+        }
+    }
+}
+

src/main/resources/config/config.yml

@@ -5,3 +5,5 @@ IvyExplicit:
     active: true
   DataClassTypedIDs:
     active: true
+  NoImplicitFunctionReturnType:
+    active: true