Ignore suppressions for no-unused-imports rule

ktlint-rule-engine-core/api/ktlint-rule-engine-core.api

@@ -358,6 +358,9 @@ public abstract interface annotation class com/pinterest/ktlint/rule/engine/core
 public abstract interface annotation class com/pinterest/ktlint/rule/engine/core/api/FeatureInBetaState : java/lang/annotation/Annotation {
 }
 
+public abstract interface class com/pinterest/ktlint/rule/engine/core/api/IgnoreKtlintSuppressions {
+}
+
 public final class com/pinterest/ktlint/rule/engine/core/api/IndentConfig {
 	public static final field Companion Lcom/pinterest/ktlint/rule/engine/core/api/IndentConfig$Companion;
 	public fun <init> (Lcom/pinterest/ktlint/rule/engine/core/api/IndentConfig$IndentStyle;I)V

ktlint-rule-engine-core/src/main/kotlin/com/pinterest/ktlint/rule/engine/core/api/IgnoreKtlintSuppressions.kt

@@ -0,0 +1,7 @@
+package com.pinterest.ktlint.rule.engine.core.api
+
+/**
+ * Marker interface to indicate that this [Rule] should ignore any rule suppression hints. This class is not intended to be used by Custom
+ * RuleSetProviders. No backward compatibility is guaranteed.
+ */
+public interface IgnoreKtlintSuppressions

ktlint-rule-engine/api/ktlint-rule-engine.api

@@ -147,7 +147,7 @@ public class com/pinterest/ktlint/rule/engine/internal/rules/InternalRule : com/
 	public fun getVisitorModifiers ()Ljava/util/Set;
 }
 
-public final class com/pinterest/ktlint/rule/engine/internal/rules/KtlintSuppressionRule : com/pinterest/ktlint/rule/engine/internal/rules/InternalRule {
+public final class com/pinterest/ktlint/rule/engine/internal/rules/KtlintSuppressionRule : com/pinterest/ktlint/rule/engine/internal/rules/InternalRule, com/pinterest/ktlint/rule/engine/core/api/IgnoreKtlintSuppressions {
 	public fun <init> (Ljava/util/List;)V
 	public fun beforeVisitChildNodes (Lorg/jetbrains/kotlin/com/intellij/lang/ASTNode;Lkotlin/jvm/functions/Function3;)V
 }

ktlint-rule-engine/src/main/kotlin/com/pinterest/ktlint/rule/engine/internal/RuleExecutionContext.kt

@@ -89,7 +89,7 @@ internal class RuleExecutionContext private constructor(
          * The [suppressionLocator] can be changed during each visit of node when running [KtLintRuleEngine.format]. So a new handler is to
          * be built before visiting the nodes.
          */
-        val suppress = suppressionLocator(node.startOffset, rule.ruleId)
+        val suppress = suppressionLocator(node.startOffset, rule)
         if (rule.shouldContinueTraversalOfAST()) {
             try {
                 if (rule is RuleAutocorrectApproveHandler) {

ktlint-rule-engine/src/main/kotlin/com/pinterest/ktlint/rule/engine/internal/SuppressionLocatorBuilder.kt

@@ -1,12 +1,13 @@
 package com.pinterest.ktlint.rule.engine.internal
 
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.RBRACE
+import com.pinterest.ktlint.rule.engine.core.api.IgnoreKtlintSuppressions
+import com.pinterest.ktlint.rule.engine.core.api.Rule
 import com.pinterest.ktlint.rule.engine.core.api.RuleId
 import com.pinterest.ktlint.rule.engine.core.api.editorconfig.EditorConfig
 import com.pinterest.ktlint.rule.engine.core.api.nextSibling
 import com.pinterest.ktlint.rule.engine.internal.SuppressionLocatorBuilder.CommentSuppressionHint.Type.BLOCK_END
 import com.pinterest.ktlint.rule.engine.internal.SuppressionLocatorBuilder.CommentSuppressionHint.Type.BLOCK_START
-import com.pinterest.ktlint.rule.engine.internal.rules.KTLINT_SUPPRESSION_RULE_ID
 import org.jetbrains.kotlin.com.intellij.lang.ASTNode
 import org.jetbrains.kotlin.com.intellij.psi.PsiComment
 import org.jetbrains.kotlin.psi.KtAnnotated
@@ -18,7 +19,7 @@ import org.jetbrains.kotlin.psi.psiUtil.startOffset
 /**
  * Detects if given `ruleId` at given `offset` is suppressed.
  */
-internal typealias SuppressionLocator = (offset: Int, ruleId: RuleId) -> Boolean
+internal typealias SuppressionLocator = (offset: Int, rule: Rule) -> Boolean
 
 internal object SuppressionLocatorBuilder {
     /**
@@ -65,15 +66,13 @@ internal object SuppressionLocatorBuilder {
     }
 
     private fun toSuppressedRegionsLocator(hintsList: List<SuppressionHint>): SuppressionLocator =
-        { offset, ruleId ->
-            if (ruleId == KTLINT_SUPPRESSION_RULE_ID) {
-                // The rule to detect deprecated rule directives may not be disabled itself as otherwise the directives
-                // will not be reported and fixed.
+        { offset, rule ->
+            if (rule is IgnoreKtlintSuppressions) {
                 false
             } else {
                 hintsList
                     .filter { offset in it.range }
-                    .any { hint -> hint.disabledRuleIds.isEmpty() || hint.disabledRuleIds.contains(ruleId.value) }
+                    .any { hint -> hint.disabledRuleIds.isEmpty() || hint.disabledRuleIds.contains(rule.ruleId.value) }
             }
         }
 

ktlint-rule-engine/src/main/kotlin/com/pinterest/ktlint/rule/engine/internal/rules/KtlintSuppressionRule.kt

@@ -8,6 +8,7 @@ import com.pinterest.ktlint.rule.engine.core.api.ElementType.BLOCK_COMMENT
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.EOL_COMMENT
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.STRING_TEMPLATE
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.VALUE_ARGUMENT
+import com.pinterest.ktlint.rule.engine.core.api.IgnoreKtlintSuppressions
 import com.pinterest.ktlint.rule.engine.core.api.RuleId
 import com.pinterest.ktlint.rule.engine.core.api.ifAutocorrectAllowed
 import com.pinterest.ktlint.rule.engine.core.api.isWhiteSpace
@@ -65,7 +66,10 @@ import org.jetbrains.kotlin.utils.addToStdlib.applyIf
  */
 public class KtlintSuppressionRule(
     private val allowedRuleIds: List<RuleId>,
-) : InternalRule("ktlint-suppression") {
+) : InternalRule("ktlint-suppression"),
+    // The SuppressionLocatorBuilder no longer support the old ktlint suppression directives using comments. This rule may not be disabled
+    // in any way as it would fail to process suppressions.
+    IgnoreKtlintSuppressions {
     private val allowedRuleIdAsStrings = allowedRuleIds.map { it.value }
 
     private val ruleIdValidator: (String) -> Boolean = { ruleId -> allowedRuleIdAsStrings.contains(ruleId) }

ktlint-rule-engine/src/test/kotlin/com/pinterest/ktlint/rule/engine/internal/SuppressionLocatorBuilderTest.kt

@@ -20,6 +20,7 @@ import com.pinterest.ktlint.rule.engine.internal.FormatterTags.Companion.FORMATT
 import com.pinterest.ktlint.rule.engine.internal.FormatterTags.Companion.FORMATTER_TAG_ON_ENABLED_PROPERTY
 import com.pinterest.ktlint.rule.engine.internal.rules.KTLINT_SUPPRESSION_RULE_ID
 import com.pinterest.ktlint.ruleset.standard.rules.IndentationRule
+import com.pinterest.ktlint.ruleset.standard.rules.NoUnusedImportsRule
 import org.assertj.core.api.Assertions.assertThat
 import org.jetbrains.kotlin.com.intellij.lang.ASTNode
 import org.junit.jupiter.api.Nested
@@ -467,6 +468,38 @@ class SuppressionLocatorBuilderTest {
         assertThat(actual).isEqualTo(formattedCode)
     }
 
+    @Test
+    fun `Issue 2696 - Given an import which is only used in a block that is suppressed then do not report that import as unused`() {
+        val code =
+            """
+            import bar.Bar1
+            import bar.Bar2
+            import bar.Bar3
+
+            fun foo123() {
+                @Suppress("ktlint")
+                Bar1()
+
+                // @formatter:off
+                Bar2()
+                // @formatter:on
+
+                Bar3()
+            }
+            """.trimIndent()
+
+        val actual =
+            lint(
+                code,
+                editorConfigOverride = EditorConfigOverride.from(FORMATTER_TAGS_ENABLED_PROPERTY to true),
+                ruleProviders = setOf(RuleProvider { NoUnusedImportsRule() }),
+            )
+        assertThat(actual).containsExactly(
+            lintError(5, 5, "standard:no-foo-identifier-standard"),
+            lintError(5, 5, "$NON_STANDARD_RULE_SET_ID:no-foo-identifier"),
+        )
+    }
+
     private class NoFooIdentifierRule(
         id: RuleId,
     ) : Rule(

ktlint-ruleset-standard/api/ktlint-ruleset-standard.api

@@ -622,7 +622,7 @@ public final class com/pinterest/ktlint/ruleset/standard/rules/NoUnitReturnRuleK
 	public static final fun getNO_UNIT_RETURN_RULE_ID ()Lcom/pinterest/ktlint/rule/engine/core/api/RuleId;
 }
 
-public final class com/pinterest/ktlint/ruleset/standard/rules/NoUnusedImportsRule : com/pinterest/ktlint/ruleset/standard/StandardRule {
+public final class com/pinterest/ktlint/ruleset/standard/rules/NoUnusedImportsRule : com/pinterest/ktlint/ruleset/standard/StandardRule, com/pinterest/ktlint/rule/engine/core/api/IgnoreKtlintSuppressions {
 	public fun <init> ()V
 	public fun afterVisitChildNodes (Lorg/jetbrains/kotlin/com/intellij/lang/ASTNode;Lkotlin/jvm/functions/Function3;)V
 	public fun beforeVisitChildNodes (Lorg/jetbrains/kotlin/com/intellij/lang/ASTNode;Lkotlin/jvm/functions/Function3;)V

ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/NoUnusedImportsRule.kt

@@ -9,6 +9,7 @@ import com.pinterest.ktlint.rule.engine.core.api.ElementType.IMPORT_DIRECTIVE
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.OPERATION_REFERENCE
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.PACKAGE_DIRECTIVE
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.REFERENCE_EXPRESSION
+import com.pinterest.ktlint.rule.engine.core.api.IgnoreKtlintSuppressions
 import com.pinterest.ktlint.rule.engine.core.api.RuleId
 import com.pinterest.ktlint.rule.engine.core.api.SinceKtlint
 import com.pinterest.ktlint.rule.engine.core.api.SinceKtlint.Status.STABLE
@@ -37,7 +38,10 @@ import org.jetbrains.kotlin.psi.KtPackageDirective
 import org.jetbrains.kotlin.resolve.ImportPath
 
 @SinceKtlint("0.2", STABLE)
-public class NoUnusedImportsRule : StandardRule("no-unused-imports") {
+public class NoUnusedImportsRule :
+    StandardRule("no-unused-imports"),
+    // Prevent that imports which are only used inside code that is suppressed are (falsely) reported as unused.
+    IgnoreKtlintSuppressions {
     private val ref =
         mutableSetOf(
             Reference("*", false),