Add escapeRegExp function

shekhargulati · Oct 16, 2017 · 025b3dd · 025b3dd
1 parent 7b552eb
commit 025b3dd
Show file tree

Hide file tree

Showing 2 changed files with 31 additions and 0 deletions.
diff --git a/src/main/java/strman/Strman.java b/src/main/java/strman/Strman.java
@@ -1404,6 +1404,11 @@ public static String[] chop(String input, int step) {
                 .toArray(String[]::new);
     }
 
+    public static String escapeRegExp(final String input) {
+        validate(input, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
+        return input.replaceAll("[\\\\\\^\\$\\*\\+\\-\\?\\.\\|\\(\\)\\{\\}\\[\\]]", "\\\\$0");
+    }
+
     private static void validate(String value, Predicate<String> predicate, final Supplier<String> supplier) {
         if (predicate.test(value)) {
             throw new IllegalArgumentException(supplier.get());

diff --git a/src/test/java/strman/StrmanTests.java b/src/test/java/strman/StrmanTests.java
@@ -1186,4 +1186,30 @@ public void chop_shouldChopStringByStep() throws Exception {
         assertThat(chop("whitespace", 3).length, equalTo(4));
         assertThat(chop("whitespace", 0)[0].length(), equalTo(10));
     }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void escapeRegExp_shouldThrowException() throws Exception {
+        escapeRegExp(null);
+    }
+
+    @Test
+    public void escapeRegExp_shouldEscapeRegExp() throws Exception {
+        assertThat(escapeRegExp("\\"), equalTo("\\\\"));
+        assertThat(escapeRegExp("^"), equalTo("\\^"));
+        assertThat(escapeRegExp("$"), equalTo("\\$"));
+        assertThat(escapeRegExp("*"), equalTo("\\*"));
+        assertThat(escapeRegExp("+"), equalTo("\\+"));
+        assertThat(escapeRegExp("-"), equalTo("\\-"));
+        assertThat(escapeRegExp("?"), equalTo("\\?"));
+        assertThat(escapeRegExp("."), equalTo("\\."));
+        assertThat(escapeRegExp("|"), equalTo("\\|"));
+        assertThat(escapeRegExp("("), equalTo("\\("));
+        assertThat(escapeRegExp(")"), equalTo("\\)"));
+        assertThat(escapeRegExp("{"), equalTo("\\{"));
+        assertThat(escapeRegExp("}"), equalTo("\\}"));
+        assertThat(escapeRegExp("["), equalTo("\\["));
+        assertThat(escapeRegExp("]"), equalTo("\\]"));
+        assertThat(escapeRegExp("How much is (2+3)? 5"), equalTo("How much is \\(2\\+3\\)\\? 5"));
+        assertThat(escapeRegExp("\\s|_|-|(?<=[a-z])(?=[A-Z])"), equalTo("\\\\s\\|_\\|\\-\\|\\(\\?<=\\[a\\-z\\]\\)\\(\\?=\\[A\\-Z\\]\\)"));
+    }
 }