Move the Selfie.expectSelfie methods into selfie-lib (#66)

selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/Selfie.kt → selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/Selfie.kt

@@ -15,31 +15,50 @@
  */
 package com.diffplug.selfie
 
-import com.diffplug.selfie.junit5.Router
-import com.diffplug.selfie.junit5.recordCall
-import java.util.Map.entry
-import org.opentest4j.AssertionFailedError
+import kotlin.jvm.JvmOverloads
+import kotlin.jvm.JvmStatic
+
+/** NOT FOR ENDUSERS. Implemented by Selfie to integrate with various test frameworks. */
+interface SnapshotStorage {
+  /** Determines if the system is in write mode or read mode. */
+  val isWrite: Boolean
+  /** Indicates that the following value should be written into test sourcecode. */
+  fun writeInline(literalValue: LiteralValue<*>)
+  /** Performs a comparison between disk and actual, writing the actual to disk if necessary. */
+  fun readWriteDisk(actual: Snapshot, sub: String): ExpectedActual
+  /**
+   * Marks that the following sub snapshots should be kept, null means to keep all snapshots for the
+   * currently executing class.
+   */
+  fun keep(subOrKeepAll: String?)
+  /** Creates an assertion failed exception to throw. */
+  fun assertFailed(message: String, expected: Any? = null, actual: Any? = null): Error
+}
+
+expect fun initStorage(): SnapshotStorage
 
 object Selfie {
+  private val storage: SnapshotStorage = initStorage()
+
   /**
    * Sometimes a selfie is environment-specific, but should not be deleted when run in a different
    * environment.
    */
   @JvmStatic
   fun preserveSelfiesOnDisk(vararg subsToKeep: String): Unit {
     if (subsToKeep.isEmpty()) {
-      Router.keep(null)
+      storage.keep(null)
     } else {
-      subsToKeep.forEach { Router.keep(it) }
+      subsToKeep.forEach { storage.keep(it) }
     }
   }
 
   class DiskSelfie internal constructor(actual: Snapshot) : LiteralStringSelfie(actual) {
     @JvmOverloads
     fun toMatchDisk(sub: String = ""): Snapshot {
-      val comparison = Router.readWriteThroughPipeline(actual, sub)
-      if (!RW.isWrite) {
-        comparison.assertEqual()
+      val comparison = storage.readWriteDisk(actual, sub)
+      if (!storage.isWrite) {
+        comparison.assertEqual(storage)
       }
       return comparison.actual
     }
@@ -58,6 +77,11 @@ object Selfie {
         check(onlyFacets.isNotEmpty()) {
           "Must have at least one facet to display, this was empty."
         }
+        if (onlyFacets.contains("")) {
+          check(onlyFacets.indexOf("") == 0) {
+            "If you're going to specify the subject facet (\"\"), you have to list it first, this was $onlyFacets"
+          }
+        }
       }
     }
     /** Extract a single facet from a snapshot in order to do an inline snapshot. */
@@ -72,16 +96,13 @@ object Selfie {
           TODO("BASE64")
         } else onlyValue.valueString()
       } else {
-        // multiple values might need our SnapshotFile escaping, we'll use it just in case
-        val facetsToCheck =
+        return serializeOnlyFacets(
+            actual,
             onlyFacets
-                ?: buildList {
+                ?: buildList<String> {
                   add("")
                   addAll(actual.facets.keys)
-                }
-        val snapshotToWrite =
-            Snapshot.ofEntries(facetsToCheck.map { entry(it, actual.subjectOrFacet(it)) })
-        return serializeMultiple(snapshotToWrite, !facetsToCheck.contains(""))
+                })
       }
     }
     fun toBe_TODO() = toBeDidntMatch(null, actualString(), LiteralString)
@@ -103,15 +124,15 @@ object Selfie {
 
   /** Implements the inline snapshot whenever a match fails. */
   private fun <T : Any> toBeDidntMatch(expected: T?, actual: T, format: LiteralFormat<T>): T {
-    if (RW.isWrite) {
-      Router.writeInline(recordCall(), LiteralValue(expected, actual, format))
+    if (storage.isWrite) {
+      storage.writeInline(LiteralValue(expected, actual, format))
       return actual
     } else {
       if (expected == null) {
-        throw AssertionFailedError(
+        throw storage.assertFailed(
             "`.toBe_TODO()` was called in `read` mode, try again with selfie in write mode")
       } else {
-        throw AssertionFailedError(
+        throw storage.assertFailed(
             "Inline literal did not match the actual value", expected, actual)
       }
     }
@@ -148,61 +169,50 @@ object Selfie {
   infix fun Boolean.shouldBeSelfie(expected: Boolean): Boolean = expectSelfie(this).toBe(expected)
 }
 
-internal class ExpectedActual(val expected: Snapshot?, val actual: Snapshot) {
-  fun assertEqual() {
+class ExpectedActual(val expected: Snapshot?, val actual: Snapshot) {
+  internal fun assertEqual(storage: SnapshotStorage) {
     if (expected == null) {
-      throw AssertionFailedError("No such snapshot")
+      throw storage.assertFailed("No such snapshot")
     } else if (expected.subject == actual.subject && expected.facets == actual.facets) {
       return
     } else {
-      val allKeys =
-          mutableSetOf<String>()
-              .apply {
-                add("")
-                addAll(expected.facets.keys)
-                addAll(actual.facets.keys)
+      val mismatchedKeys =
+          sequence {
+                yield("")
+                yieldAll(expected.facets.keys)
+                for (facet in actual.facets.keys) {
+                  if (!expected.facets.containsKey(facet)) {
+                    yield(facet)
+                  }
+                }
               }
+              .filter { expected.subjectOrFacetMaybe(it) != actual.subjectOrFacetMaybe(it) }
               .toList()
               .sorted()
-      val mismatchInExpected = mutableMapOf<String, SnapshotValue>()
-      val mismatchInActual = mutableMapOf<String, SnapshotValue>()
-      for (key in allKeys) {
-        val expectedValue = expected.facets[key]
-        val actualValue = actual.facets[key]
-        if (expectedValue != actualValue) {
-          expectedValue?.let { mismatchInExpected[key] = it }
-          actualValue?.let { mismatchInActual[key] = it }
-        }
-      }
-      val includeRoot = mismatchInExpected.containsKey("")
-      throw AssertionFailedError(
+      throw storage.assertFailed(
           "Snapshot failure",
-          serializeMultiple(Snapshot.ofEntries(mismatchInExpected.entries), !includeRoot),
-          serializeMultiple(Snapshot.ofEntries(mismatchInActual.entries), !includeRoot))
+          serializeOnlyFacets(expected, mismatchedKeys),
+          serializeOnlyFacets(actual, mismatchedKeys))
     }
   }
 }
-private fun serializeMultiple(actual: Snapshot, removeEmptySubject: Boolean): String {
-  if (removeEmptySubject) {
-    check(actual.subject.valueString().isEmpty()) {
-      "The subject was expected to be empty, was '${actual.subject.valueString()}'"
-    }
-  }
-  val file = SnapshotFile()
-  file.snapshots = ArrayMap.of(mutableListOf("" to actual))
+/**
+ * Returns a serialized form of only the given facets if they are available, silently omits missing
+ * facets.
+ */
+private fun serializeOnlyFacets(snapshot: Snapshot, keys: Collection<String>): String {
   val buf = StringBuilder()
-  file.serialize(buf::append)
-
-  check(buf.startsWith(EMPTY_SUBJECT))
-  check(buf.endsWith(EOF))
-  buf.setLength(buf.length - EOF.length)
-  val str = buf.substring(EMPTY_SUBJECT.length)
-  return if (!removeEmptySubject) str
-  else {
-    check(str[0] == '\n')
-    str.substring(1)
+  val writer = StringWriter { buf.append(it) }
+  for (key in keys) {
+    if (key.isEmpty()) {
+      SnapshotFile.writeValue(writer, snapshot.subjectOrFacet(key))
+    } else {
+      snapshot.subjectOrFacetMaybe(key)?.let {
+        SnapshotFile.writeKey(writer, "", key)
+        SnapshotFile.writeValue(writer, it)
+      }
+    }
   }
+  buf.setLength(buf.length - 1)
+  return buf.toString()
 }
-
-private const val EMPTY_SUBJECT = "╔═  ═╗\n"
-private const val EOF = "\n╔═ [end of file] ═╗\n"

selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/SnapshotFile.kt

@@ -156,28 +156,6 @@ class SnapshotFile {
     }
     writeKey(valueWriter, "", "end of file")
   }
-  private fun writeKey(valueWriter: StringWriter, key: String, facet: String?) {
-    valueWriter.write("╔═ ")
-    valueWriter.write(SnapshotValueReader.nameEsc.escape(key))
-    if (facet != null) {
-      valueWriter.write("[")
-      valueWriter.write(SnapshotValueReader.nameEsc.escape(facet))
-      valueWriter.write("]")
-    }
-    valueWriter.write(" ═╗\n")
-  }
-  private fun writeValue(valueWriter: StringWriter, value: SnapshotValue) {
-    if (value.isBinary) {
-      TODO("BASE64")
-    } else {
-      val escaped =
-          SnapshotValueReader.bodyEsc
-              .escape(value.valueString())
-              .efficientReplace("\n╔", "\n\uD801\uDF41")
-      valueWriter.write(escaped)
-      valueWriter.write("\n")
-    }
-  }
 
   var wasSetAtTestTime: Boolean = false
   fun setAtTestTime(key: String, snapshot: Snapshot) {
@@ -222,6 +200,28 @@ class SnapshotFile {
       result.unixNewlines = unixNewlines
       return result
     }
+    internal fun writeKey(valueWriter: StringWriter, key: String, facet: String?) {
+      valueWriter.write("╔═ ")
+      valueWriter.write(SnapshotValueReader.nameEsc.escape(key))
+      if (facet != null) {
+        valueWriter.write("[")
+        valueWriter.write(SnapshotValueReader.nameEsc.escape(facet))
+        valueWriter.write("]")
+      }
+      valueWriter.write(" ═╗\n")
+    }
+    internal fun writeValue(valueWriter: StringWriter, value: SnapshotValue) {
+      if (value.isBinary) {
+        TODO("BASE64")
+      } else {
+        val escaped =
+            SnapshotValueReader.bodyEsc
+                .escape(value.valueString())
+                .efficientReplace("\n╔", "\n\uD801\uDF41")
+        valueWriter.write(escaped)
+        valueWriter.write("\n")
+      }
+    }
   }
 }
 

selfie-lib/src/jsMain/kotlin/com/diffplug/selfie/Selfie.js.kt

@@ -0,0 +1,19 @@
+/*
+ * 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
+actual fun initStorage(): SnapshotStorage {
+  TODO("Not yet implemented")
+}

selfie-lib/src/jvmMain/kotlin/com/diffplug/selfie/Selfie.jvm.kt

@@ -0,0 +1,25 @@
+/*
+ * 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
+actual fun initStorage(): SnapshotStorage {
+  try {
+    val clazz = Class.forName("com.diffplug.selfie.junit5.SnapshotStorageJUnit5")
+    return clazz.getMethod("initStorage").invoke(null) as SnapshotStorage
+  } catch (e: ClassNotFoundException) {
+    throw IllegalStateException(
+        "Missing required artifact `com.diffplug.spotless:selfie-runner-junit5", e)
+  }
+}

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

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.diffplug.selfie
+package com.diffplug.selfie.junit5
 
 /**
  * Determines whether Selfie is overwriting snapshots or erroring-out on mismatch.

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

@@ -17,7 +17,6 @@ package com.diffplug.selfie.junit5
 
 import com.diffplug.selfie.*
 import com.diffplug.selfie.ExpectedActual
-import com.diffplug.selfie.RW
 import java.nio.charset.StandardCharsets
 import java.nio.file.Files
 import java.nio.file.Path
@@ -29,17 +28,22 @@ import org.junit.platform.engine.support.descriptor.MethodSource
 import org.junit.platform.launcher.TestExecutionListener
 import org.junit.platform.launcher.TestIdentifier
 import org.junit.platform.launcher.TestPlan
+import org.opentest4j.AssertionFailedError
 
 /** Routes between `toMatchDisk()` calls and the snapshot file / pruning machinery. */
-internal object Router {
+internal object SnapshotStorageJUnit5 : SnapshotStorage {
+  @JvmStatic fun initStorage(): SnapshotStorage = this
+  override val isWrite: Boolean
+    get() = RW.isWrite
+
   private class ClassMethod(val clazz: ClassProgress, val method: String)
   private val threadCtx = ThreadLocal<ClassMethod?>()
   private fun classAndMethod() =
       threadCtx.get()
           ?: throw AssertionError(
               "Selfie `toMatchDisk` must be called only on the original thread.")
   private fun suffix(sub: String) = if (sub == "") "" else "/$sub"
-  fun readWriteThroughPipeline(actual: Snapshot, sub: String): ExpectedActual {
+  override fun readWriteDisk(actual: Snapshot, sub: String): ExpectedActual {
     val cm = classAndMethod()
     val suffix = suffix(sub)
     val callStack = recordCall()
@@ -50,15 +54,19 @@ internal object Router {
       ExpectedActual(cm.clazz.read(cm.method, suffix), actual)
     }
   }
-  fun keep(subOrKeepAll: String?) {
+  override fun keep(subOrKeepAll: String?) {
     val cm = classAndMethod()
     if (subOrKeepAll == null) {
       cm.clazz.keep(cm.method, null)
     } else {
       cm.clazz.keep(cm.method, suffix(subOrKeepAll))
     }
   }
-  fun writeInline(call: CallStack, literalValue: LiteralValue<*>) {
+  override fun assertFailed(message: String, expected: Any?, actual: Any?): Error =
+      if (expected == null && actual == null) AssertionFailedError(message)
+      else AssertionFailedError(message, expected, actual)
+  override fun writeInline(literalValue: LiteralValue<*>) {
+    val call = recordCall()
     val cm =
         threadCtx.get()
             ?: throw AssertionError("Selfie `toBe` must be called only on the original thread.")
@@ -100,13 +108,13 @@ internal class ClassProgress(val parent: Progress, val className: String) {
   // the methods below called by the TestExecutionListener on its runtime thread
   @Synchronized fun startMethod(method: String) {
     assertNotTerminated()
-    Router.start(this, method)
+    SnapshotStorageJUnit5.start(this, method)
     assert(method.indexOf('/') == -1) { "Method name cannot contain '/', was $method" }
     methods = methods.plus(method, MethodSnapshotGC())
   }
   @Synchronized fun finishedMethodWithSuccess(method: String, success: Boolean) {
     assertNotTerminated()
-    Router.finish(this, method)
+    SnapshotStorageJUnit5.finish(this, method)
     methods[method]!!.succeeded(success)
   }
   @Synchronized fun finishedClassWithSuccess(success: Boolean) {

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

@@ -16,7 +16,6 @@
 package com.diffplug.selfie.junit5
 
 import com.diffplug.selfie.LiteralValue
-import com.diffplug.selfie.RW
 import com.diffplug.selfie.Snapshot
 import com.diffplug.selfie.SourceFile
 import java.nio.file.Files