From e850d761205eb56ec4ff513daa24530f893684d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Brais=20Gab=C3=ADn?= <braisgabin@gmail.com>
Date: Sat, 30 Apr 2022 13:41:07 +0200
Subject: [PATCH 1/2] Report as warnings the Strings that should be an array

---
 .../detekt/core/config/ValidateConfig.kt      | 11 +++++++++
 .../detekt/core/config/ValidateConfigSpec.kt  | 23 +++++++++++++++++++
 .../resources/config_validation/baseline.yml  |  2 ++
 3 files changed, 36 insertions(+)

diff --git a/detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt b/detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt
index 331dbaf5bb1..002c4ada1b3 100644
--- a/detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt
+++ b/detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt
@@ -99,6 +99,8 @@ internal fun validateConfig(
 
             if (!base.contains(prop)) {
                 notifications.add(propertyDoesNotExists(propertyPath))
+            } else if (current[prop] is String && base[prop] is List<*>) {
+                notifications.add(propertyShouldBeAnArray(propertyPath, warningsAsErrors))
             }
 
             val next = current[prop] as? Map<String, Any>
@@ -140,3 +142,12 @@ internal fun propertyIsDeprecated(
         "Property '$prop' is deprecated. $deprecationDescription.",
         if (reportAsError) Notification.Level.Error else Notification.Level.Warning,
     )
+
+internal fun propertyShouldBeAnArray(
+    prop: String,
+    reportAsError: Boolean,
+): Notification =
+    SimpleNotification(
+        "Property '$prop' should be an array instead of a String.",
+        if (reportAsError) Notification.Level.Error else Notification.Level.Warning,
+    )
diff --git a/detekt-core/src/test/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfigSpec.kt b/detekt-core/src/test/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfigSpec.kt
index 81b41bb41d1..a67f6d93e70 100644
--- a/detekt-core/src/test/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfigSpec.kt
+++ b/detekt-core/src/test/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfigSpec.kt
@@ -224,4 +224,27 @@ class ValidateConfigSpec {
             )
         }
     }
+
+    @ParameterizedTest
+    @ValueSource(booleans = [true, false])
+    fun `reports a string that should be an array as a warning`(warningsAsErrors: Boolean) {
+        val config = yamlConfigFromContent(
+            """
+                config:
+                  warningsAsErrors: $warningsAsErrors
+                style:
+                  MagicNumber:
+                    ignoreNumbers: '-1,0,1,2'
+            """.trimIndent()
+        )
+
+        val result = validateConfig(config, baseline)
+
+        assertThat(result).contains(
+            propertyShouldBeAnArray(
+                "style>MagicNumber>ignoreNumbers",
+                reportAsError = warningsAsErrors
+            )
+        )
+    }
 }
diff --git a/detekt-core/src/test/resources/config_validation/baseline.yml b/detekt-core/src/test/resources/config_validation/baseline.yml
index 222505f1294..dc814e5a41a 100644
--- a/detekt-core/src/test/resources/config_validation/baseline.yml
+++ b/detekt-core/src/test/resources/config_validation/baseline.yml
@@ -1,3 +1,5 @@
+config:
+  warningsAsErrors: true
 complexity:
   LongMethod:
     active: true

From b0a63123caea388e435166fc7a30968c393f1265 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Brais=20Gab=C3=ADn?= <braisgabin@gmail.com>
Date: Sat, 30 Apr 2022 20:36:57 +0200
Subject: [PATCH 2/2] Update
 detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt

Co-authored-by: Nicola Corti <corti.nico@gmail.com>
---
 .../io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt b/detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt
index 002c4ada1b3..4f6dfe62d52 100644
--- a/detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt
+++ b/detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/config/ValidateConfig.kt
@@ -148,6 +148,6 @@ internal fun propertyShouldBeAnArray(
     reportAsError: Boolean,
 ): Notification =
     SimpleNotification(
-        "Property '$prop' should be an array instead of a String.",
+        "Property '$prop' should be a YAML array instead of a comma-separated String.",
         if (reportAsError) Notification.Level.Error else Notification.Level.Warning,
     )