From 16b5adcc4dd4e1fcb88e79c7415bf04eeb16c158 Mon Sep 17 00:00:00 2001
From: Svyatoslav Chatchenko <mydogtom@gmail.com>
Date: Wed, 20 Jun 2018 15:01:38 +0200
Subject: [PATCH] Rule: NoSpaceBetweenParentheses

New rule forbids redundant spaces between parentheses. Fixes #223
---
 .../standard/NoSpaceBetweenParentheses.kt     | 36 +++++++++++++++++
 .../standard/StandardRuleSetProvider.kt       |  1 +
 .../standard/NoSpaceBetweenParenthesesTest.kt | 40 +++++++++++++++++++
 3 files changed, 77 insertions(+)
 create mode 100644 ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoSpaceBetweenParentheses.kt
 create mode 100644 ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoSpaceBetweenParenthesesTest.kt

diff --git a/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoSpaceBetweenParentheses.kt b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoSpaceBetweenParentheses.kt
new file mode 100644
index 0000000000..951c2d61a7
--- /dev/null
+++ b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoSpaceBetweenParentheses.kt
@@ -0,0 +1,36 @@
+package com.github.shyiko.ktlint.ruleset.standard
+
+import com.github.shyiko.ktlint.core.Rule
+import org.jetbrains.kotlin.com.intellij.lang.ASTNode
+import org.jetbrains.kotlin.com.intellij.psi.PsiWhiteSpace
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.psiUtil.siblings
+
+class NoSpaceBetweenParentheses : Rule("no-space-between-parentheses") {
+
+    override fun visit(node: ASTNode, autoCorrect: Boolean, emit: (offset: Int, errorMessage: String, canBeAutoCorrected: Boolean) -> Unit) {
+        if (node.elementType == KtTokens.LPAR) {
+            val iterator = node.siblings().iterator()
+            var foundEnclosingPar = false
+            var hasSpaces = false
+            while (iterator.hasNext() && !foundEnclosingPar) {
+                val nextNode = iterator.next()
+                if (!hasSpaces && nextNode is PsiWhiteSpace) {
+                    hasSpaces = true
+                } else if (nextNode.elementType == KtTokens.RPAR) {
+                    foundEnclosingPar = true
+                } else {
+                    // the case when there are parameters or multiline declaration
+                    break
+                }
+            }
+            if (hasSpaces && foundEnclosingPar) {
+                emit(node.startOffset + 1, "Unexpected space between parentheses", true)
+                if (autoCorrect) {
+                    val enclosingPar = node.siblings().first { it.elementType == KtTokens.RPAR }
+                    node.treeParent.removeRange(node.siblings().first(), enclosingPar)
+                }
+            }
+        }
+    }
+}
diff --git a/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/StandardRuleSetProvider.kt b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/StandardRuleSetProvider.kt
index 87f06b4254..26c58539ce 100644
--- a/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/StandardRuleSetProvider.kt
+++ b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/StandardRuleSetProvider.kt
@@ -24,6 +24,7 @@ class StandardRuleSetProvider : RuleSetProvider {
         NoLineBreakBeforeAssignmentRule(),
         NoMultipleSpacesRule(),
         NoSemicolonsRule(),
+        NoSpaceBetweenParentheses(),
         NoTrailingSpacesRule(),
         NoUnitReturnRule(),
         NoUnusedImportsRule(),
diff --git a/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoSpaceBetweenParenthesesTest.kt b/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoSpaceBetweenParenthesesTest.kt
new file mode 100644
index 0000000000..0f7ab5a185
--- /dev/null
+++ b/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/NoSpaceBetweenParenthesesTest.kt
@@ -0,0 +1,40 @@
+package com.github.shyiko.ktlint.ruleset.standard
+
+import com.github.shyiko.ktlint.core.LintError
+import com.github.shyiko.ktlint.test.format
+import com.github.shyiko.ktlint.test.lint
+import org.assertj.core.api.Assertions.assertThat
+import org.testng.annotations.Test
+
+class NoSpaceBetweenParenthesesTest {
+    @Test
+    fun testFailWhenEncounterSpace() {
+        assertThat(NoSpaceBetweenParentheses().lint("fun main( ) {}"))
+            .isEqualTo(listOf(
+                LintError(1, 10, "no-space-between-parentheses", "Unexpected space between parentheses")
+            ))
+    }
+
+    @Test
+    fun testNoFailureWhenOnlyParentheses() {
+        assertThat(NoSpaceBetweenParentheses().lint("fun main() {}"))
+            .isEmpty()
+    }
+
+    @Test
+    fun testNoFailureWhenMultilineDeclaration() {
+        assertThat(NoSpaceBetweenParentheses().lint(
+            """
+                fun main(
+                  val a: String
+                ) {}
+             """
+        )).isEmpty()
+    }
+
+    @Test
+    fun testAutoFormat() {
+        assertThat(NoSpaceBetweenParentheses().format("fun main( ) {}"))
+            .isEqualTo("fun main() {}")
+    }
+}