Improved filename rule (#194)

5 files changed, 193 insertions, 121 deletions

diff --git a/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/ClassNameMatchesFileNameRule.kt b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/ClassNameMatchesFileNameRule.kt
deleted file mode 100644
index 9622c2bf..00000000
--- a/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/ClassNameMatchesFileNameRule.kt
+++ /dev/null
@@ -1,39 +0,0 @@
-package com.github.shyiko.ktlint.ruleset.standard
-
-import com.github.shyiko.ktlint.core.KtLint
-import com.github.shyiko.ktlint.core.Rule
-import org.jetbrains.kotlin.com.intellij.lang.ASTNode
-import org.jetbrains.kotlin.lexer.KtTokens
-import org.jetbrains.kotlin.psi.stubs.elements.KtStubElementTypes
-import java.nio.file.Paths
-
-/**
- * If there is only one top level class in a given file, then its name should match the file's name
- */
-class ClassNameMatchesFileNameRule : Rule("class-name-matches-file-name"), Rule.Modifier.RestrictToRoot {
-
-    override fun visit(
-        node: ASTNode,
-        autoCorrect: Boolean,
-        emit: (offset: Int, errorMessage: String, canBeAutoCorrected: Boolean) -> Unit
-    ) {
-        val filePath = node.getUserData(KtLint.FILE_PATH_USER_DATA_KEY)
-
-        // Ignore all non ".kt" files (including ".kts")
-        if (filePath?.endsWith(".kt") != true) {
-            return
-        }
-
-        val topLevelClassNames = node.getChildren(null)
-            .filter { it.elementType == KtStubElementTypes.CLASS }
-            .mapNotNull { it.findChildByType(KtTokens.IDENTIFIER)?.text }
-
-        val name = Paths.get(filePath).fileName.toString().substringBefore(".")
-        if (topLevelClassNames.size == 1 && name != topLevelClassNames.first()) {
-            val className = topLevelClassNames.first()
-            emit(0,
-                "Class $className should be declared in a file named $className.kt",
-                false)
-        }
-    }
-}
diff --git a/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/FilenameRule.kt b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/FilenameRule.kt
new file mode 100644
index 00000000..8c7169c8
--- /dev/null
+++ b/ktlint-ruleset-standard/src/main/kotlin/com/github/shyiko/ktlint/ruleset/standard/FilenameRule.kt
@@ -0,0 +1,63 @@
+package com.github.shyiko.ktlint.ruleset.standard
+
+import com.github.shyiko.ktlint.core.KtLint
+import com.github.shyiko.ktlint.core.Rule
+import org.jetbrains.kotlin.com.intellij.lang.ASTNode
+import org.jetbrains.kotlin.com.intellij.psi.tree.IElementType
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.psiUtil.getPrevSiblingIgnoringWhitespaceAndComments
+import org.jetbrains.kotlin.psi.stubs.elements.KtStubElementTypes
+import java.nio.file.Paths
+
+/**
+ * If there is only one top level class/object/typealias in a given file, then its name should match the file's name.
+ */
+class FilenameRule : Rule("filename"), Rule.Modifier.RestrictToRoot {
+
+    private val ignoreSet = setOf<IElementType>(
+        KtStubElementTypes.FILE_ANNOTATION_LIST,
+        KtStubElementTypes.PACKAGE_DIRECTIVE,
+        KtStubElementTypes.IMPORT_LIST,
+        KtTokens.WHITE_SPACE,
+        KtTokens.EOL_COMMENT,
+        KtTokens.BLOCK_COMMENT,
+        KtTokens.DOC_COMMENT,
+        KtTokens.SHEBANG_COMMENT
+    )
+
+    override fun visit(
+        node: ASTNode,
+        autoCorrect: Boolean,
+        emit: (offset: Int, errorMessage: String, canBeAutoCorrected: Boolean) -> Unit
+    ) {
+        val filePath = node.getUserData(KtLint.FILE_PATH_USER_DATA_KEY)
+        if (filePath?.endsWith(".kt") != true) {
+            // ignore all non ".kt" files (including ".kts")
+            return
+        }
+        var type: String? = null
+        var className: String? = null
+        for (el in node.getChildren(null)) {
+            if (el.elementType == KtStubElementTypes.CLASS ||
+                el.elementType == KtStubElementTypes.OBJECT_DECLARATION ||
+                el.elementType == KtStubElementTypes.TYPEALIAS) {
+                if (className != null) {
+                    // more than one class/object/typealias present
+                    return
+                }
+                val id = el.findChildByType(KtTokens.IDENTIFIER)
+                type = id?.psi?.getPrevSiblingIgnoringWhitespaceAndComments(false)?.text
+                className = id?.text
+            } else if (!ignoreSet.contains(el.elementType)) {
+                // https://github.com/android/android-ktx/blob/master/src/main/java/androidx/core/graphics/Path.kt case
+                return
+            }
+        }
+        if (className != null) {
+            val name = Paths.get(filePath).fileName.toString().substringBefore(".")
+            if (name != "package" && name != className) {
+                emit(0, "$type $className should be declared in a file named $className.kt", false)
+            }
+        }
+    }
+}
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 39ba666c..87f06b42 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
@@ -8,7 +8,7 @@ class StandardRuleSetProvider : RuleSetProvider {
     override fun get(): RuleSet = RuleSet("standard",
         ChainWrappingRule(),
         CommentSpacingRule(),
-        ClassNameMatchesFileNameRule(),
+        FilenameRule(),
         FinalNewlineRule(),
         // disabled until it's clear how to reconcile difference in Intellij & Android Studio import layout
         // ImportOrderingRule(),
diff --git a/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/ClassNameMatchesFileNameRuleTest.kt b/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/ClassNameMatchesFileNameRuleTest.kt
deleted file mode 100644
index e57759b8..00000000
--- a/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/ClassNameMatchesFileNameRuleTest.kt
+++ /dev/null
@@ -1,81 +0,0 @@
-package com.github.shyiko.ktlint.ruleset.standard
-
-import com.github.shyiko.ktlint.core.LintError
-import com.github.shyiko.ktlint.test.lint
-import org.assertj.core.api.Assertions.assertThat
-import org.testng.annotations.Test
-
-class ClassNameMatchesFileNameRuleTest {
-
-    @Test
-    fun testMatchingSingleClassName() {
-        assertThat(ClassNameMatchesFileNameRule().lint(
-            """
-                class A
-            """.trimIndent(),
-            fileName("/some/path/A.kt")
-        )).isEmpty()
-    }
-
-    @Test
-    fun testNonMatchingSingleClassName() {
-        assertThat(ClassNameMatchesFileNameRule().lint(
-            """
-                class B
-            """.trimIndent(),
-            fileName("A.kt")
-        )).isEqualTo(listOf(
-            LintError(1, 1, "class-name-matches-file-name", "Class B should be declared in a file named B.kt")
-        ))
-    }
-
-    @Test
-    fun testMultipleTopLevelClasses() {
-        assertThat(ClassNameMatchesFileNameRule().lint(
-            """
-                class B
-                class C
-            """.trimIndent(),
-            fileName("A.kt")
-        )).isEmpty()
-    }
-
-    @Test
-    fun testMultipleNonTopLevelClasses() {
-        assertThat(ClassNameMatchesFileNameRule().lint(
-            """
-                class B {
-                    class C
-                    class D
-                }
-            """.trimIndent(),
-            fileName("A.kt")
-        )).isEqualTo(listOf(
-            LintError(1, 1, "class-name-matches-file-name", "Class B should be declared in a file named B.kt")
-        ))
-    }
-
-    @Test
-    fun testCaseSensitiveMatching() {
-        assertThat(ClassNameMatchesFileNameRule().lint(
-            """
-                interface Woohoo
-            """.trimIndent(),
-            fileName("woohoo.kt")
-        )).isEqualTo(listOf(
-            LintError(1, 1, "class-name-matches-file-name", "Class Woohoo should be declared in a file named Woohoo.kt")
-        ))
-    }
-
-    @Test
-    fun testIgnoreKotlinScriptFiles() {
-        assertThat(ClassNameMatchesFileNameRule().lint(
-            """
-                class B
-            """.trimIndent(),
-            fileName("A.kts")
-        )).isEmpty()
-    }
-
-    private fun fileName(fileName: String) = mapOf("file_path" to fileName)
-}
diff --git a/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/FilenameRuleTest.kt b/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/FilenameRuleTest.kt
new file mode 100644
index 00000000..84e7ad4a
--- /dev/null
+++ b/ktlint-ruleset-standard/src/test/kotlin/com/github/shyiko/ktlint/ruleset/standard/FilenameRuleTest.kt
@@ -0,0 +1,129 @@
+package com.github.shyiko.ktlint.ruleset.standard
+
+import com.github.shyiko.ktlint.core.LintError
+import com.github.shyiko.ktlint.test.lint
+import org.assertj.core.api.Assertions.assertThat
+import org.testng.annotations.Test
+
+class FilenameRuleTest {
+
+    @Test
+    fun testMatchingSingleClassName() {
+        for (src in listOf(
+            "class A",
+            "data class A(val v: Int)",
+            "sealed class A",
+            "interface A",
+            "object A",
+            "enum class A {A}",
+            "typealias A = Set<Network.Node>",
+            // >1 declaration case
+            "class B\nfun A.f() {}"
+        )) {
+            assertThat(FilenameRule().lint(
+                """
+                /*
+                 * license
+                 */
+                @file:JvmName("Foo")
+                package x
+                import y.Z
+                $src
+                //
+                """.trimIndent(),
+                fileName("/some/path/A.kt")
+            )).isEmpty()
+        }
+    }
+
+    @Test
+    fun testNonMatchingSingleClassName() {
+        for (src in mapOf(
+            "class A" to "class",
+            "data class A(val v: Int)" to "class",
+            "sealed class A" to "class",
+            "interface A" to "interface",
+            "object A" to "object",
+            "enum class A {A}" to "class",
+            "typealias A = Set<Network.Node>" to "typealias"
+        )) {
+            assertThat(FilenameRule().lint(
+                """
+                /*
+                 * license
+                 */
+                @file:JvmName("Foo")
+                package x
+                import y.Z
+                ${src.key}
+                //
+                """.trimIndent(),
+                fileName("/some/path/B.kt")
+            )).isEqualTo(listOf(
+                LintError(1, 1, "filename", "${src.value} A should be declared in a file named A.kt")
+            ))
+        }
+    }
+
+    @Test
+    fun testFileWithoutTopLevelDeclarations() {
+        assertThat(FilenameRule().lint(
+            """
+            /*
+             * copyright
+             */
+            """.trimIndent(),
+            fileName("A.kt")
+        )).isEmpty()
+    }
+
+    @Test
+    fun testMultipleTopLevelClasses() {
+        assertThat(FilenameRule().lint(
+            """
+            class B
+            class C
+            """.trimIndent(),
+            fileName("A.kt")
+        )).isEmpty()
+    }
+
+    @Test
+    fun testMultipleNonTopLevelClasses() {
+        assertThat(FilenameRule().lint(
+            """
+            class B {
+                class C
+                class D
+            }
+            """.trimIndent(),
+            fileName("A.kt")
+        )).isEqualTo(listOf(
+            LintError(1, 1, "filename", "class B should be declared in a file named B.kt")
+        ))
+    }
+
+    @Test
+    fun testCaseSensitiveMatching() {
+        assertThat(FilenameRule().lint(
+            """
+            interface Woohoo
+            """.trimIndent(),
+            fileName("woohoo.kt")
+        )).isEqualTo(listOf(
+            LintError(1, 1, "filename", "interface Woohoo should be declared in a file named Woohoo.kt")
+        ))
+    }
+
+    @Test
+    fun testIgnoreKotlinScriptFiles() {
+        assertThat(FilenameRule().lint(
+            """
+            class B
+            """.trimIndent(),
+            fileName("A.kts")
+        )).isEmpty()
+    }
+
+    private fun fileName(fileName: String) = mapOf("file_path" to fileName)
+}