Add MatchersTest

dd-trace-core/src/main/java/datadog/trace/core/util/GlobPattern.java

@@ -5,20 +5,11 @@
 public final class GlobPattern {
 
   public static Pattern globToRegexPattern(String globPattern) {
-    if (globPattern == null) {
-      return null;
-    }
     String regex = globToRegex(globPattern);
-    if (regex == null) {
-      return null;
-    }
     return Pattern.compile(regex);
   }
 
   private static String globToRegex(String globPattern) {
-    if ("*".equals(globPattern)) {
-      return null;
-    }
     StringBuilder sb = new StringBuilder(64);
     sb.append('^');
     for (int i = 0; i < globPattern.length(); i++) {

dd-trace-core/src/main/java/datadog/trace/core/util/Matchers.java

@@ -19,15 +19,15 @@ public static final Matcher compileGlob(String glob) {
     }
   }
 
-  public static final boolean matches(Matcher matcher, String str) {
+  public static boolean matches(Matcher matcher, String str) {
     return (matcher == null) || matcher.matches(str);
   }
 
-  public static final boolean matches(Matcher matcher, CharSequence charSeq) {
+  public static boolean matches(Matcher matcher, CharSequence charSeq) {
     return (matcher == null) || matcher.matches(charSeq);
   }
 
-  static final boolean isExact(String glob) {
+  static boolean isExact(String glob) {
     return (glob.indexOf('*') == -1) && (glob.indexOf('?') == -1);
   }
 
@@ -39,7 +39,7 @@ static final class ExactMatcher implements Matcher {
     }
 
     @Override
-    public final boolean matches(String str) {
+    public boolean matches(String str) {
       return exact.equals(str);
     }
 

dd-trace-core/src/test/groovy/datadog/trace/core/util/GlobPatternTest.groovy

@@ -10,9 +10,13 @@ class GlobPatternTest extends DDSpecification {
 
     where:
     globPattern | expectedRegex
-    "*"         | null
+    "*"         | "^.*\$"
+    "?"         | "^.\$"
+    "??"        | "^..\$"
     "Foo*"      | "^Foo.*\$"
     "abc"       | "^abc\$"
     "?"         | "^.\$"
+    "F?o"       | "^F.o\$"
+    "Bar*"      | "^Bar.*\$"
   }
 }

dd-trace-core/src/test/groovy/datadog/trace/core/util/MatchersTest.groovy

@@ -0,0 +1,54 @@
+package datadog.trace.core.util
+
+import datadog.trace.test.util.DDSpecification
+
+class MatchersTest extends DDSpecification {
+
+  def "match-all scenarios must return a null matcher"() {
+    expect:
+    Matchers.compileGlob(glob) == null
+
+    where:
+    glob << [null, "*"]
+  }
+
+  def "pattern without * or ? must be an ExactMatcher"() {
+    expect:
+    Matchers.compileGlob(glob) instanceof Matchers.ExactMatcher
+
+    where:
+    glob << ["a", "ogre", "bcoho34e2"]
+  }
+
+  def "pattern with either * or ? must be a PatternMatcher"() {
+    expect:
+    Matchers.compileGlob(glob) instanceof Matchers.PatternMatcher
+
+    where:
+    glob << ["?", "foo*", "*bar", "F?oB?r", "F?o*", "?*", "*?"]
+  }
+
+  def "an exact matcher is self matching"() {
+    expect:
+    Matchers.compileGlob(pattern).matches(pattern)
+
+    where:
+    pattern << ["", "a", "abc", "cde"]
+  }
+
+  def "a pattern matcher test"() {
+    when:
+    def matcher = Matchers.compileGlob(pattern)
+
+    then:
+    matcher.matches(matching)
+    !matcher.matches(nonMatching)
+
+    where:
+    pattern | matching | nonMatching
+    "Fo?"   | "Foo"    | "Fooo"
+    "Fo*"   | "Fo"     | "Fa"
+    "F*B?r" | "FooBar" | "FooFar"
+    ""      | ""       | "non-empty"
+  }
+}