From 443ba01abc87d2a82bb74931744e72d3de5ed442 Mon Sep 17 00:00:00 2001
From: JelloRanger <jacob@jabramson.com>
Date: Thu, 25 Jan 2018 22:02:42 -0800
Subject: [PATCH 1/2] Add unit test to verify that custom componentN operator
 functions aren't marked as unused imports

---
 .../standard/NoUnusedImportsRuleTest.kt       | 29 +++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoUnusedImportsRuleTest.kt b/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoUnusedImportsRuleTest.kt
index 2384ffa9f1..65d1b74467 100644
--- a/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoUnusedImportsRuleTest.kt
+++ b/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoUnusedImportsRuleTest.kt
@@ -47,6 +47,35 @@ class NoUnusedImportsRuleTest {
         )).isEmpty()
     }
 
+    @Test
+    fun testDestructureOperatorLint() {
+        assertThat(NoUnusedImportsRule().lint(
+            """
+            import p.component6
+
+            fun main() {
+                val (one, two, three, four, five, six) = someList
+            }
+            """.trimIndent()
+        )).isEmpty()
+        assertThat(NoUnusedImportsRule().lint(
+            """
+            import p.component6
+            import p.component2
+            import p.component100
+            import p.component
+            import p.component12woohoo
+
+            fun main() {
+                val (one, two, three, four, five, six) = someList
+            }
+            """.trimIndent()
+        )).isEqualTo(listOf(
+            LintError(4, 1, "no-unused-imports", "Unused import"),
+            LintError(5, 1, "no-unused-imports", "Unused import")
+        ))
+    }
+
     @Test
     fun testLintKDocLinkImport() {
         assertThat(NoUnusedImportsRule().lint(

From 4d13e87749b91465f6f8e4ad4574cc63bc6d794b Mon Sep 17 00:00:00 2001
From: JelloRanger <jacob@jabramson.com>
Date: Thu, 25 Jan 2018 22:23:49 -0800
Subject: [PATCH 2/2] Fix KtLint erroneously marking custom componentN
 operators as unused

- Devs can write custom componentN operators in order to allow
  destructuring blocks of > 5 values, i.e.

    inline operator fun <T> component6 = get(5)

which allows the following (which is NOT possible without the above
extension method):

   val (one, two, three, four, five, six) = someList
                                     ^--- component6() is imported to
make this possible

- In order to avoid marking these imports as unused we can ignore all
  imports that match componentX (where X is any number)
---
 .../shyiko/ktlint/ruleset/standard/NoUnusedImportsRule.kt | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoUnusedImportsRule.kt b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoUnusedImportsRule.kt
index f7e9ce7bd0..32255b48b4 100644
--- a/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoUnusedImportsRule.kt
+++ b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoUnusedImportsRule.kt
@@ -12,6 +12,8 @@ import org.jetbrains.kotlin.psi.stubs.elements.KtStubElementTypes
 
 class NoUnusedImportsRule : Rule("no-unused-imports") {
 
+    private val destructureOperator = Regex("(?:component)[\\d]+\\b")
+
     private val operatorSet = setOf(
         // unary
         "unaryPlus", "unaryMinus", "not",
@@ -34,9 +36,7 @@ class NoUnusedImportsRule : Rule("no-unused-imports") {
         // iteration (https://github.com/shyiko/ktlint/issues/40)
         "iterator",
         // by (https://github.com/shyiko/ktlint/issues/54)
-        "getValue", "setValue",
-        // destructuring assignment
-        "component1", "component2", "component3", "component4", "component5"
+        "getValue", "setValue"
     )
     private val ref = mutableSetOf<String>()
     private var packageName = ""
@@ -74,7 +74,7 @@ class NoUnusedImportsRule : Rule("no-unused-imports") {
                 if (autoCorrect) {
                     importDirective.delete()
                 }
-            } else if (name != null && !ref.contains(name) && !operatorSet.contains(name)) {
+            } else if (name != null && !ref.contains(name) && !operatorSet.contains(name) && !destructureOperator.matches(name)) {
                 emit(importDirective.startOffset, "Unused import", true)
                 if (autoCorrect) {
                     importDirective.delete()