2 files changed, 71 insertions, 0 deletions
diff --git a/src/test/java/org/shedlang/compiler/SourceFilesTests.java b/src/test/java/org/shedlang/compiler/SourceFilesTests.java
new file mode 100644
index 00000000..d904d057
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/SourceFilesTests.java
@@ -0,0 +1,57 @@
+package org.shedlang.compiler;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.types.NamespaceName;
+
+import java.io.IOException;
+import java.nio.file.Files;
+
+import static org.shedlang.compiler.TemporaryFiles.createTemporaryTestDirectory;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.*;
+
+public class SourceFilesTests {
+    @Test
+    public void whenDirectoryIsEmptyThenNoSourceFilesAreFound() throws IOException {
+        var sourceDirectory = createTemporaryTestDirectory("SourceFilesTests");
+
+        var sourceFiles = SourceFiles.collectSourceFiles(sourceDirectory);
+
+        assertThat(sourceFiles, containsExactly());
+    }
+
+    @Test
+    public void whenDirectoryContainsFileWithShedExtensionThenSourceFileIsFound() throws IOException {
+        var sourceDirectory = createTemporaryTestDirectory("SourceFilesTests");
+        Files.createFile(sourceDirectory.resolve("One.shed"));
+
+        var sourceFiles = SourceFiles.collectSourceFiles(sourceDirectory);
+
+        assertThat(sourceFiles, containsExactly(
+            allOf(
+                has("path", x -> x.path(), equalTo(sourceDirectory.resolve("One.shed"))),
+                has("namespaceName", x -> x.namespaceName(), equalTo(NamespaceName.of("One")))
+            )
+        ));
+    }
+
+    @Test
+    public void whenDirectoryContainsFileWithNonShedExtensionThenNoSourceFileIsFound() throws IOException {
+        var sourceDirectory = createTemporaryTestDirectory("SourceFilesTests");
+        Files.createFile(sourceDirectory.resolve("One.she"));
+
+        var sourceFiles = SourceFiles.collectSourceFiles(sourceDirectory);
+
+        assertThat(sourceFiles, containsExactly());
+    }
+
+    @Test
+    public void whenFileHasMultipleThenExtensionsThenFileIsNotTreatedAsSourceFile() throws IOException {
+        var sourceDirectory = createTemporaryTestDirectory("SourceFilesTests");
+        Files.createFile(sourceDirectory.resolve("One.Two.shed"));
+
+        var sourceFiles = SourceFiles.collectSourceFiles(sourceDirectory);
+
+        assertThat(sourceFiles, containsExactly());
+    }
+}
diff --git a/src/test/java/org/shedlang/compiler/TemporaryFiles.java b/src/test/java/org/shedlang/compiler/TemporaryFiles.java
new file mode 100644
index 00000000..bfe084c6
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/TemporaryFiles.java
@@ -0,0 +1,14 @@
+package org.shedlang.compiler;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class TemporaryFiles {
+    private TemporaryFiles() {}
+
+    public static Path createTemporaryTestDirectory(String name) throws IOException {
+        Files.createDirectories(Path.of("tests-tmp"));
+        return Files.createTempDirectory(Path.of("tests-tmp"), name);
+    }
+}