Added tests for autolink feature

app/src/main/java/eu/faircode/email/HtmlHelper.java

@@ -111,11 +111,7 @@ public class HtmlHelper {
             public void head(Node node, int depth) {
                 if (node instanceof TextNode) {
                     String text = Html.escapeHtml(((TextNode) node).text());
-                    Matcher matcher = pattern.matcher(text);
+                    text = autolink(text);
-                    while (matcher.find()) {
-                        String ref = matcher.group();
-                        text = text.replace(ref, String.format("<a href=\"%s\">%s</a>", ref, ref));
-                    }
                     node.before(text);
                     ((TextNode) node).text("");
                 }
@@ -129,6 +125,15 @@ public class HtmlHelper {
         return document.body().html();
     }
 
+    static String autolink(String text) {
+        Matcher matcher = pattern.matcher(text);
+        while (matcher.find()) {
+            String ref = matcher.group();
+            text = text.replace(ref, String.format("<a href=\"%s\">%s</a>", ref, ref));
+        }
+        return text;
+    }
+
     static Drawable decodeImage(String source, Context context, long id, boolean show) {
         int px = Helper.dp2pixels(context, 48);
 

app/src/test/java/eu/faircode/email/HtmlHelperTest.java

@@ -0,0 +1,56 @@
+package eu.faircode.email;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class HtmlHelperTest {
+
+    @Test
+    void autolink() {
+
+        testAutolink(
+                "To visit http://www.example.org, go to http://www.example.org.",
+
+                "" +
+                        // FIXME: The trailing comma must not be part of the URL.
+                        "To visit <a href=\"http://www.example.org,\">http://www.example.org,</a> " +
+                        // FIXME: The trailing dot must not be part of the URL.
+                        "go to <a href=\"http://www.example.org.\">http://www.example.org.</a>");
+
+        testAutolink(
+                "one hhhhh|spt://example.org three",
+
+                // FIXME: "hhhhh|spt" is not a proper URL scheme.
+                "one <a href=\"hhhhh|spt://example.org\">hhhhh|spt://example.org</a> three"
+        );
+
+        testAutolink(
+                "https://example.org/search?q=%C3%A4&hl=nl",
+
+                // TODO: Strictly speaking, the & should be encoded as &amp;.
+                // Most browsers can deal with this situation though.
+                "<a href=\"https://example.org/search?q=%C3%A4&hl=nl\">" +
+                        "https://example.org/search?q=%C3%A4&hl=nl</a>"
+        );
+
+        testAutolink(
+                "Go to \"http://example.org/\".",
+
+                // FIXME: The quote must not end up as part of the URL.
+                "Go to \"<a href=\"http://example.org/\".\">http://example.org/\".</a>"
+        );
+
+        testAutolink(
+                "Go to <http://example.org/>.",
+
+                // FIXME: The < must be encoded as &lt;.
+                // FIXME: THe > must not end up as part of the URL.
+                "Go to <<a href=\"http://example.org/>.\">http://example.org/>.</a>"
+        );
+    }
+
+    private void testAutolink(String input, String expectedOutput) {
+        assertThat(HtmlHelper.autolink(input)).isEqualTo(expectedOutput);
+    }
+}