add support for contains, starts, and ends

Update to be consistent with recent changes to Atlas
backend to support `:contains`, `:starts`, and `:ends`
query operations. These get mapped to regex so it only
impacts the query parsing.

See: Netflix/atlas#1470 and Netflix/atlas#1471.

spectator-reg-atlas/src/main/java/com/netflix/spectator/atlas/impl/Parser.java

@@ -15,6 +15,8 @@
  */
 package com.netflix.spectator.atlas.impl;
 
+import com.netflix.spectator.impl.matcher.PatternUtils;
+
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Deque;
@@ -156,6 +158,21 @@ private static Object parse(String expr) {
           k = (String) stack.pop();
           pushRegex(stack, new Query.Regex(k, v, true, ":reic"));
           break;
+        case ":contains":
+          v = (String) stack.pop();
+          k = (String) stack.pop();
+          pushRegex(stack, new Query.Regex(k, ".*" + PatternUtils.escape(v)));
+          break;
+        case ":starts":
+          v = (String) stack.pop();
+          k = (String) stack.pop();
+          pushRegex(stack, new Query.Regex(k, PatternUtils.escape(v)));
+          break;
+        case ":ends":
+          v = (String) stack.pop();
+          k = (String) stack.pop();
+          pushRegex(stack, new Query.Regex(k, ".*" + PatternUtils.escape(v) + "$"));
+          break;
         case ":all":
           q = (Query) stack.pop();
           stack.push(new DataExpr.All(q));

spectator-reg-atlas/src/test/java/com/netflix/spectator/atlas/impl/QueryTest.java

@@ -42,7 +42,10 @@ private Query parse(String expr) {
     Query q1 = Parser.parseQuery(expr);
     Query q2 = Parser.parseQuery(expr);
     Assertions.assertEquals(q1, q2);
-    Assertions.assertEquals(expr, q1.toString());
+
+    Query q3 = Parser.parseQuery(q1.toString());
+    Assertions.assertEquals(q1, q3);
+    Assertions.assertEquals(q1.toString(), q3.toString());
     return q1;
   }
 
@@ -210,6 +213,63 @@ public void reEqualsContract() {
         .verify();
   }
 
+  @Test
+  public void containsQuery() {
+    Query q = parse("name,foo,:contains");
+    Assertions.assertTrue(q.matches(registry.createId("foo")));
+    Assertions.assertTrue(q.matches(registry.createId("foo_")));
+    Assertions.assertTrue(q.matches(registry.createId("_foo_")));
+    Assertions.assertTrue(q.matches(registry.createId("_foo")));
+    Assertions.assertFalse(q.matches(registry.createId("_Foo_")));
+  }
+
+  @Test
+  public void containsQueryEscape() {
+    Query q = parse("name,^$.?*+[](){}\\#&!%,:contains");
+    Assertions.assertEquals(
+        "name,.*\\^\\$\\.\\?\\*\\+\\[\\]\\(\\)\\{\\}\\\\#&!%,:re",
+        q.toString());
+    Assertions.assertTrue(q.matches(registry.createId("^$.?*+[](){}\\#&!%")));
+  }
+
+  @Test
+  public void startsQuery() {
+    Query q = parse("name,foo,:starts");
+    Assertions.assertTrue(q.matches(registry.createId("foo")));
+    Assertions.assertTrue(q.matches(registry.createId("foo_")));
+    Assertions.assertFalse(q.matches(registry.createId("_foo_")));
+    Assertions.assertFalse(q.matches(registry.createId("_foo")));
+    Assertions.assertFalse(q.matches(registry.createId("Foo_")));
+  }
+
+  @Test
+  public void startsQueryEscape() {
+    Query q = parse("name,^$.?*+[](){}\\#&!%,:starts");
+    Assertions.assertEquals(
+        "name,\\^\\$\\.\\?\\*\\+\\[\\]\\(\\)\\{\\}\\\\#&!%,:re",
+        q.toString());
+    Assertions.assertTrue(q.matches(registry.createId("^$.?*+[](){}\\#&!%")));
+  }
+
+  @Test
+  public void endsQuery() {
+    Query q = parse("name,foo,:ends");
+    Assertions.assertTrue(q.matches(registry.createId("foo")));
+    Assertions.assertFalse(q.matches(registry.createId("foo_")));
+    Assertions.assertFalse(q.matches(registry.createId("_foo_")));
+    Assertions.assertTrue(q.matches(registry.createId("_foo")));
+    Assertions.assertFalse(q.matches(registry.createId("_Foo")));
+  }
+
+  @Test
+  public void endsQueryEscape() {
+    Query q = parse("name,^$.?*+[](){}\\#&!%,:ends");
+    Assertions.assertEquals(
+        "name,.*\\^\\$\\.\\?\\*\\+\\[\\]\\(\\)\\{\\}\\\\#&!%$,:re",
+        q.toString());
+    Assertions.assertTrue(q.matches(registry.createId("^$.?*+[](){}\\#&!%")));
+  }
+
   @Test
   public void andQuery() {
     Query q = parse("name,foo,:eq,bar,baz,:eq,:and");