Fix classpath relative-to-absolute conversion in DotenvReader (#27)

* Fix classpath relative-to-absolute conversion in DotenvReader

Escape "." to prevent removing the trailing character from a simple directory name with no leading "/" or "./"

Anchor the regex to prevents stripping a trailing literal "." from a directory name, which is unlikely but possible

Add tests for simple resource directory and resource directory with trailing "."

Examples of bug:
.directory("envdir") would try to load "resources/envdi/.env" and fail.
.directory("/trailingdot./envdir") would try to load "resources/trailingdot/envdir/.env") and fail.

* Rename dirTest to assertDirectory to satisfy Codacy Static Code Analysis

Co-authored-by: Clement Cherlin <ccherlin@dminc.com>

src/main/java/io/github/cdimascio/dotenv/internal/DotenvReader.java

@@ -54,7 +54,7 @@ public List<String> read() throws DotenvException, IOException {
 
         try {
             return ClasspathHelper
-                .loadFileFromClasspath(location.replaceFirst("./", "/"))
+                .loadFileFromClasspath(location.replaceFirst("^\\./", "/"))
                 .collect(Collectors.toList());
         } catch (DotenvException e) {
             Path cwd = FileSystems.getDefault().getPath(".").toAbsolutePath().normalize();

src/test/java/tests/BasicTests.java

@@ -66,6 +66,36 @@ public void resourceRelative() {
         assertHostEnvVar(dotenv);
     }
 
+    @Test
+    public void resourceAbsoluteDir() {
+        assertDirectory("/envdir","Simple Subdirectory");
+    }
+
+    @Test
+    public void resourceRelativeDir() {
+        assertDirectory("./envdir", "Simple Subdirectory");
+    }
+
+    @Test
+    public void resourceUnanchoredDir() {
+        assertDirectory("envdir", "Simple Subdirectory");
+    }
+
+    @Test
+    public void resourceAbsoluteTrailingDotDir() {
+        assertDirectory("/trailingdot./envdir", "Trailing Dot Directory With Subdirectory");
+    }
+
+    @Test
+    public void resourceRelativeTrailingDotDir() {
+        assertDirectory("./trailingdot./envdir", "Trailing Dot Directory With Subdirectory");
+    }
+
+    @Test
+    public void resourceUnanchoredTrailingDotDir() {
+        assertDirectory("trailingdot./envdir", "Trailing Dot Directory With Subdirectory");
+    }
+
     @Test
     public void resourceCurrent() {
         var dotenv = Dotenv.configure()
@@ -130,6 +160,13 @@ public void dotenvIgnoreMissing() {
         assertNull(dotenv.get("MY_TEST_EV1"));
     }
 
+    private void assertDirectory(String directory, String expected) {
+        var dotenv = Dotenv.configure()
+            .directory(directory)
+            .load();
+        assertEquals(expected, dotenv.get("MY_TEST_EV1"));
+    }
+
     private void assertHostEnvVar(Dotenv env) {
         var isWindows = System.getProperty("os.name").toLowerCase().contains("win");
         if (isWindows) {

src/test/resources/envdir/.env

@@ -0,0 +1,2 @@
+## Good test EV
+MY_TEST_EV1=Simple Subdirectory

src/test/resources/trailingdot./envdir/.env

@@ -0,0 +1,2 @@
+## Good test EV
+MY_TEST_EV1=Trailing Dot Directory With Subdirectory