A provisional API to implement memoizing of regular and suspending fu…

…nctions.

jvm/selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/SelfieMemo.kt

@@ -0,0 +1,94 @@
+package com.diffplug.selfie
+
+import com.diffplug.selfie.guts.DiskSnapshotTodo
+import com.diffplug.selfie.guts.DiskStorage
+import com.diffplug.selfie.guts.LiteralFormat
+import com.diffplug.selfie.guts.LiteralString
+import com.diffplug.selfie.guts.LiteralValue
+import com.diffplug.selfie.guts.SnapshotSystem
+import com.diffplug.selfie.guts.recordCall
+import kotlin.jvm.JvmOverloads
+
+class StringMemo(val disk: DiskStorage, val generator: () -> String) {
+    @JvmOverloads
+    fun toMatchDisk(sub: String = "") : String {
+        val call = recordCall(false)
+        if (Selfie.system.mode.canWrite(false, call, Selfie.system)) {
+            val actual = generator()
+            disk.writeDisk(Snapshot.of(actual), sub, call)
+            return actual
+        } else {
+            val snapshot = disk.readDisk(sub, call)
+                    ?: throw Selfie.system.fs.assertFailed(Selfie.system.mode.msgSnapshotNotFound())
+            if (snapshot.subject.isBinary || snapshot.facets.isNotEmpty()) {
+                throw Selfie.system.fs.assertFailed("Expected a string subject with no facets, got ${snapshot}")
+            }
+            return snapshot.subject.valueString()
+        }
+    }
+    @JvmOverloads
+    fun toMatchDisk_TODO(sub: String = "") : String {
+        val call = recordCall(false)
+        if (Selfie.system.mode.canWrite(true, call, Selfie.system)) {
+            val actual = generator()
+            disk.writeDisk(Snapshot.of(actual), sub, call)
+            Selfie.system.writeInline(DiskSnapshotTodo.createLiteral(), call)
+            return actual
+        } else {
+            throw Selfie.system.fs.assertFailed("Can't call `toMatchDisk_TODO` in ${Mode.readonly} mode!")
+        }
+    }
+    @JvmOverloads
+    fun toBe_TODO(unusedArg: Any? = null) : String {
+        val call = recordCall(false)
+        val writable = Selfie.system.mode.canWrite(true, call, Selfie.system)
+        if (writable) {
+            val actual = generator()
+            Selfie.system.writeInline(LiteralValue(null, actual, LiteralString), call)
+            return actual
+        } else {
+            throw Selfie.system.fs.assertFailed("Can't call `toBe_TODO` in ${Mode.readonly} mode!")
+        }
+    }
+    fun toBe(expected: String) : String = expected
+}
+class StringMemoSuspend(val disk: DiskStorage, val generator: suspend () -> String) {
+    suspend fun toMatchDisk(sub: String = "") : String {
+        val call = recordCall(false)
+        if (Selfie.system.mode.canWrite(false, call, Selfie.system)) {
+            val actual = generator()
+            disk.writeDisk(Snapshot.of(actual), sub, call)
+            return actual
+        } else {
+            val snapshot = disk.readDisk(sub, call)
+                    ?: throw Selfie.system.fs.assertFailed(Selfie.system.mode.msgSnapshotNotFound())
+            if (snapshot.subject.isBinary || snapshot.facets.isNotEmpty()) {
+                throw Selfie.system.fs.assertFailed("Expected a string subject with no facets, got ${snapshot}")
+            }
+            return snapshot.subject.valueString()
+        }
+    }
+    suspend fun toMatchDisk_TODO(sub: String = "") : String {
+        val call = recordCall(false)
+        if (Selfie.system.mode.canWrite(true, call, Selfie.system)) {
+            val actual = generator()
+            disk.writeDisk(Snapshot.of(actual), sub, call)
+            Selfie.system.writeInline(DiskSnapshotTodo.createLiteral(), call)
+            return actual
+        } else {
+            throw Selfie.system.fs.assertFailed("Can't call `toMatchDisk_TODO` in ${Mode.readonly} mode!")
+        }
+    }
+    suspend fun toBe_TODO(unusedArg: Any? = null) : String {
+        val call = recordCall(false)
+        val writable = Selfie.system.mode.canWrite(true, call, Selfie.system)
+        if (writable) {
+            val actual = generator()
+            Selfie.system.writeInline(LiteralValue(null, actual, LiteralString), call)
+            return actual
+        } else {
+            throw Selfie.system.fs.assertFailed("Can't call `toBe_TODO` in ${Mode.readonly} mode!")
+        }
+    }
+    fun toBe(expected: String) : String = expected
+}