Merge pull request #13 from diffplug/feat/gc-within-method

"Sub" snapshots.

selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/junit5/SelfieGC.kt

@@ -103,7 +103,7 @@ internal class MethodSnapshotGC {
             continue
           } else if (key.elementAt(gc.key.length) == '/') {
             // startWith + not same length = can safely query the `/`
-            val suffix = key.substring(gc.key.length + 1)
+            val suffix = key.substring(gc.key.length)
             if (!gc.value.keeps(suffix)) {
               staleIndices.add(keyIdx)
             }
@@ -162,6 +162,7 @@ internal class MethodSnapshotGC {
     private val EMPTY_SET = ArraySet<String>(arrayOf())
   }
 }
+
 /** An immutable, sorted, array-backed set. */
 internal class ArraySet<K : Comparable<K>>(private val data: Array<Any>) : ListBackedSet<K>() {
   override val size: Int

selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/WithinMethodGCTest.kt

@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2023 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.selfie.junit5
+
+import kotlin.test.Test
+import org.junit.jupiter.api.MethodOrderer
+import org.junit.jupiter.api.Order
+import org.junit.jupiter.api.TestMethodOrder
+import org.junitpioneer.jupiter.DisableIfTestFails
+
+/** Write-only test which asserts adding and removing snapshots results in same-class GC. */
+@TestMethodOrder(MethodOrderer.OrderAnnotation::class)
+@DisableIfTestFails
+class WithinMethodGCTest : Harness("undertest-junit5") {
+  @Test @Order(1)
+  fun noSelfiesNoFile() {
+    ut_snapshot().deleteIfExists()
+    ut_snapshot().assertDoesNotExist()
+    ut_mirror().linesFrom("UT_WithinMethodGC").toLast("}").shrinkByOne().commentOut()
+  }
+
+  @Test @Order(2)
+  fun rootOnly() {
+    ut_mirror().linesFrom("fun selfie()").toFirst("}").uncomment()
+    ut_mirror().lineWith("maple").commentOut()
+    gradleWriteSS()
+    ut_snapshot()
+        .assertContent(
+            """
+      ╔═ selfie ═╗
+      root
+      ╔═ [end of file] ═╗
+      
+    """
+                .trimIndent())
+  }
+
+  @Test @Order(3)
+  fun rootAndLeaf() {
+    ut_mirror().lineWith("maple").uncomment()
+    gradleWriteSS()
+    ut_snapshot()
+        .assertContent(
+            """
+      ╔═ selfie ═╗
+      root
+      ╔═ selfie/leaf ═╗
+      maple
+      ╔═ [end of file] ═╗
+      
+    """
+                .trimIndent())
+  }
+
+  @Test @Order(4)
+  fun leafOnly() {
+    ut_mirror().lineWith("root").commentOut()
+    gradleWriteSS()
+    ut_snapshot()
+        .assertContent(
+            """
+      ╔═ selfie/leaf ═╗
+      maple
+      ╔═ [end of file] ═╗
+      
+    """
+                .trimIndent())
+  }
+
+  @Test @Order(5)
+  fun renameTheWholeMethod() {
+    ut_mirror().lineWith("selfie2()").uncomment()
+    ut_mirror().lineWith("selfie()").commentOut()
+    gradleWriteSS()
+    ut_snapshot()
+        .assertContent(
+            """
+      ╔═ selfie2/leaf ═╗
+      maple
+      ╔═ [end of file] ═╗
+      
+    """
+                .trimIndent())
+  }
+
+  @Test @Order(6)
+  fun resetUTMirror() {
+    ut_mirror().lineWith("root").uncomment()
+    ut_mirror().lineWith("selfie2()").commentOut()
+    ut_mirror().lineWith("selfie()").uncomment()
+  }
+
+  @Test @Order(7)
+  fun deleteSelfie() {
+    ut_snapshot().deleteIfExists()
+  }
+}

undertest-junit5/src/test/kotlin/undertest/junit5/UT_WithinMethodGCTest.kt

@@ -0,0 +1,14 @@
+package com.diffplug.selfie.junit5
+// spotless:off
+import com.diffplug.selfie.expectSelfie
+import kotlin.test.Test
+
+// spotless:on
+
+class UT_WithinMethodGCTest {
+//    @Test fun selfie2() {
+  @Test fun selfie() {
+    expectSelfie("root").toMatchDisk()
+    expectSelfie("maple").toMatchDisk("leaf")
+  }
+}