Misc Changes

app/src/main/java/solutions/tretter/githugandroid/levels/CheckoutFileLevel.kt

@@ -0,0 +1,21 @@
+package solutions.tretter.githugandroid
+
+/**
+ * Port of the upstream ruby-githug `checkout_file` level.
+ *
+ * Setup documents the repository shape the learner explores. Evaluation is kept
+ * state-based whenever the exercise changes repository objects; answer-only
+ * levels intentionally validate the answer entered at the prompt.
+ */
+internal fun checkoutFileLevel(): Level = level(
+    id = "checkout_file",
+    title = "Checkout File",
+    description = "A file has been modified, but you don't want to keep the modification. Checkout the `config.rb` file from the last commit.",
+    hints = listOf("You will need to do some research on the checkout command for this one."),
+    commandSuggestions = listOf("git checkout -- config.rb"),
+    setup = { RepoState(initialized = true, files = listOf(GitFile("config.rb", "This is the initial config file\nThese are changes you don't want to keep!", tracked = true)), commits = listOf(CommitNode("0000001", "Added initial config file")), branches = mapOf("master" to 1)) },
+    validator = repoPredicate { repo -> repo.files.find { it.name == "config.rb" }?.content == "This is the initial config file" },
+    testCases = listOf(
+        levelTestCase("checkout file from head", "git checkout -- config.rb"),
+    ),
+)