Merge pull request #1749 from HaidarJbeily7/master

Feat: add support for negative value to get tail from the string
yegor256 · Nov 26, 2024 · 4482ed9 · 4482ed9
2 parents b6f0d63 + 7a0f591
commit 4482ed9
Show file tree

Hide file tree

Showing 2 changed files with 37 additions and 1 deletion.
diff --git a/src/main/java/org/cactoos/text/Sub.java b/src/main/java/org/cactoos/text/Sub.java
@@ -148,13 +148,22 @@ public Sub(final Text text, final Func<? super String, Integer> start,
             new Mapped(
                 origin -> {
                     int begin = start.apply(origin);
+                    if (begin < 0) {
+                        begin = origin.length() + begin;
+                    }
                     if (begin < 0) {
                         begin = 0;
                     }
                     int finish = end.apply(origin);
-                    if (origin.length() < finish) {
+                    if (finish < 0) {
+                        finish = origin.length() + finish;
+                    }
+                    if (finish > origin.length()) {
                         finish = origin.length();
                     }
+                    if (finish < 0) {
+                        finish = 0;
+                    }
                     return origin.substring(begin, finish);
                 },
                 text

diff --git a/src/test/java/org/cactoos/text/SubTest.java b/src/test/java/org/cactoos/text/SubTest.java
@@ -67,4 +67,31 @@ void cutTextWithStart() {
         ).affirm();
     }
 
+    @Test
+    void cutTextWithNegativeStart() {
+        new Assertion<>(
+            "Can't cut text with negative start",
+            new Sub("hello world", -5),
+            new HasString("world")
+        ).affirm();
+    }
+
+    @Test
+    void cutTextWithNegativeStartAndEnd() {
+        new Assertion<>(
+            "Can't cut text with negative start and positive end",
+            new Sub("hello world", -5, 8),
+            new HasString("wo")
+        ).affirm();
+    }
+
+    @Test
+    void cutTextWithNegativeStartAndNegativeEnd() {
+        new Assertion<>(
+            "Can't cut text with negative start and negative end",
+            new Sub("hello world", -5, -2),
+            new HasString("wor")
+        ).affirm();
+    }
+
 }