EQL: Add case handling to stringContains (#58762) (#58813)

Co-authored-by: Ross Wolf <31489089+rw-access@users.noreply.github.com>
(cherry picked from commit 1a58776d3aa563beb364b067a1db46497122306f)

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringContains.java

@@ -6,13 +6,15 @@
 
 package org.elasticsearch.xpack.eql.expression.function.scalar.string;
 
+import org.elasticsearch.xpack.eql.session.EqlConfiguration;
 import org.elasticsearch.xpack.ql.expression.Expression;
 import org.elasticsearch.xpack.ql.expression.Expressions;
 import org.elasticsearch.xpack.ql.expression.FieldAttribute;
-import org.elasticsearch.xpack.ql.expression.function.scalar.ScalarFunction;
+import org.elasticsearch.xpack.ql.expression.function.scalar.string.CaseSensitiveScalarFunction;
 import org.elasticsearch.xpack.ql.expression.gen.pipeline.Pipe;
 import org.elasticsearch.xpack.ql.expression.gen.script.ScriptTemplate;
 import org.elasticsearch.xpack.ql.expression.gen.script.Scripts;
+import org.elasticsearch.xpack.ql.session.Configuration;
 import org.elasticsearch.xpack.ql.tree.NodeInfo;
 import org.elasticsearch.xpack.ql.tree.Source;
 import org.elasticsearch.xpack.ql.type.DataType;
@@ -32,12 +34,12 @@ import static org.elasticsearch.xpack.ql.expression.gen.script.ParamsBuilder.par
  * stringContains(a, b)
  * Returns true if b is a substring of a
  */
-public class StringContains extends ScalarFunction {
+public class StringContains extends CaseSensitiveScalarFunction {
 
     private final Expression string, substring;
 
-    public StringContains(Source source, Expression string, Expression substring) {
+    public StringContains(Source source, Expression string, Expression substring, Configuration configuration) {
-        super(source, Arrays.asList(string, substring));
+        super(source, Arrays.asList(string, substring), configuration);
         this.string = string;
         this.substring = substring;
     }
@@ -59,7 +61,7 @@ public class StringContains extends ScalarFunction {
     @Override
     protected Pipe makePipe() {
         return new StringContainsFunctionPipe(source(), this,
-                Expressions.pipe(string), Expressions.pipe(substring));
+                Expressions.pipe(string), Expressions.pipe(substring), isCaseSensitive());
     }
 
     @Override
@@ -69,12 +71,12 @@ public class StringContains extends ScalarFunction {
 
     @Override
     public Object fold() {
-        return doProcess(string.fold(), substring.fold());
+        return doProcess(string.fold(), substring.fold(), isCaseSensitive());
     }
 
     @Override
     protected NodeInfo<? extends Expression> info() {
-        return NodeInfo.create(this, StringContains::new, string, substring);
+        return NodeInfo.create(this, StringContains::new, string, substring, eqlConfiguration());
     }
 
     @Override
@@ -83,13 +85,15 @@ public class StringContains extends ScalarFunction {
     }
 
     protected ScriptTemplate asScriptFrom(ScriptTemplate stringScript, ScriptTemplate substringScript) {
-        return new ScriptTemplate(format(Locale.ROOT, formatTemplate("{eql}.%s(%s,%s)"),
+        return new ScriptTemplate(format(Locale.ROOT, formatTemplate("{eql}.%s(%s,%s,%s)"),
                 "stringContains",
                 stringScript.template(),
-                substringScript.template()),
+                substringScript.template(),
+                "{}"),
                 paramsBuilder()
                     .script(stringScript.params())
                     .script(substringScript.params())
+                    .variable(isCaseSensitive())
                     .build(), dataType());
     }
 
@@ -111,6 +115,15 @@ public class StringContains extends ScalarFunction {
             throw new IllegalArgumentException("expected [2] children but received [" + newChildren.size() + "]");
         }
 
-        return new StringContains(source(), newChildren.get(0), newChildren.get(1));
+        return new StringContains(source(), newChildren.get(0), newChildren.get(1), eqlConfiguration());
+    }
+
+    public EqlConfiguration eqlConfiguration() {
+        return (EqlConfiguration) configuration();
+    }
+
+    @Override
+    public boolean isCaseSensitive() {
+        return eqlConfiguration().isCaseSensitive();
     }
 }

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringContainsFunctionPipe.java

@@ -19,11 +19,13 @@ import java.util.Objects;
 public class StringContainsFunctionPipe extends Pipe {
 
     private final Pipe string, substring;
+    private final boolean isCaseSensitive;
 
-    public StringContainsFunctionPipe(Source source, Expression expression, Pipe string, Pipe substring) {
+    public StringContainsFunctionPipe(Source source, Expression expression, Pipe string, Pipe substring, boolean isCaseSensitive) {
         super(source, expression, Arrays.asList(string, substring));
         this.string = string;
         this.substring = substring;
+        this.isCaseSensitive = isCaseSensitive;
     }
 
     @Override
@@ -55,7 +57,7 @@ public class StringContainsFunctionPipe extends Pipe {
     }
 
     protected StringContainsFunctionPipe replaceChildren(Pipe string, Pipe substring) {
-        return new StringContainsFunctionPipe(source(), expression(), string, substring);
+        return new StringContainsFunctionPipe(source(), expression(), string, substring, isCaseSensitive);
     }
 
     @Override
@@ -66,12 +68,12 @@ public class StringContainsFunctionPipe extends Pipe {
 
     @Override
     protected NodeInfo<StringContainsFunctionPipe> info() {
-        return NodeInfo.create(this, StringContainsFunctionPipe::new, expression(), string, substring);
+        return NodeInfo.create(this, StringContainsFunctionPipe::new, expression(), string, substring, isCaseSensitive);
     }
 
     @Override
     public StringContainsFunctionProcessor asProcessor() {
-        return new StringContainsFunctionProcessor(string.asProcessor(), substring.asProcessor());
+        return new StringContainsFunctionProcessor(string.asProcessor(), substring.asProcessor(), isCaseSensitive);
     }
 
     public Pipe string() {
@@ -82,6 +84,9 @@ public class StringContainsFunctionPipe extends Pipe {
         return substring;
     }
 
+    protected boolean isCaseSensitive() {
+        return isCaseSensitive;
+    }
 
     @Override
     public int hashCode() {

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringContainsFunctionProcessor.java

@@ -19,29 +19,33 @@ public class StringContainsFunctionProcessor implements Processor {
     public static final String NAME = "sstc";
 
     private final Processor string, substring;
+    private final boolean isCaseSensitive;
 
-    public StringContainsFunctionProcessor(Processor string, Processor substring) {
+    public StringContainsFunctionProcessor(Processor string, Processor substring, boolean isCaseSensitive) {
         this.string = string;
         this.substring = substring;
+        this.isCaseSensitive = isCaseSensitive;
     }
 
     public StringContainsFunctionProcessor(StreamInput in) throws IOException {
         string = in.readNamedWriteable(Processor.class);
         substring = in.readNamedWriteable(Processor.class);
+        isCaseSensitive = in.readBoolean();
     }
 
     @Override
     public final void writeTo(StreamOutput out) throws IOException {
         out.writeNamedWriteable(string);
         out.writeNamedWriteable(substring);
+        out.writeBoolean(isCaseSensitive);
     }
 
     @Override
     public Object process(Object input) {
-        return doProcess(string.process(input), substring.process(input));
+        return doProcess(string.process(input), substring.process(input), isCaseSensitive);
     }
 
-    public static Object doProcess(Object string, Object substring) {
+    public static Object doProcess(Object string, Object substring, boolean isCaseSensitive) {
         if (string == null) {
             return null;
         }
@@ -51,7 +55,8 @@ public class StringContainsFunctionProcessor implements Processor {
 
         String strString = string.toString();
         String strSubstring = substring.toString();
-        return StringUtils.stringContains(strString, strSubstring);
+
+        return StringUtils.stringContains(strString, strSubstring, isCaseSensitive);
     }
 
     private static void throwIfNotString(Object obj) {

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringUtils.java

@@ -65,15 +65,19 @@ final class StringUtils {
      *
      * @param string    string to search through.
      * @param substring string to search for.
+     * @param isCaseSensitive toggle for case sensitivity.
      * @return {@code true} if {@code string} string contains {@code substring} string.
      */
-    static boolean stringContains(String string, String substring) {
+    static boolean stringContains(String string, String substring, boolean isCaseSensitive) {
         if (hasLength(string) == false || hasLength(substring) == false) {
             return false;
         }
 
+        if (isCaseSensitive == false) {
             string = string.toLowerCase(Locale.ROOT);
             substring = substring.toLowerCase(Locale.ROOT);
+        }
+
         return string.contains(substring);
     }
 

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/expression/function/scalar/whitelist/InternalEqlScriptUtils.java

@@ -57,8 +57,8 @@ public class InternalEqlScriptUtils extends InternalQlScriptUtils {
         return (String) ToStringFunctionProcessor.doProcess(s);
     }
 
-    public static Boolean stringContains(String string, String substring) {
+    public static Boolean stringContains(String string, String substring, Boolean isCaseSensitive) {
-        return (Boolean) StringContainsFunctionProcessor.doProcess(string, substring);
+        return (Boolean) StringContainsFunctionProcessor.doProcess(string, substring, isCaseSensitive);
     }
 
     public static Number number(String source, Number base) {

x-pack/plugin/eql/src/main/resources/org/elasticsearch/xpack/eql/plugin/eql_whitelist.txt

@@ -73,6 +73,6 @@ class org.elasticsearch.xpack.eql.expression.function.scalar.whitelist.InternalE
   Integer length(String)
   Number  number(String, Number)
   String  string(Object)
-  Boolean stringContains(String, String)
+  Boolean stringContains(String, String, Boolean)
   String  substring(String, Number, Number)
 }

x-pack/plugin/eql/src/test/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringContainsFunctionPipeTests.java

@@ -6,6 +6,7 @@
 
 package org.elasticsearch.xpack.eql.expression.function.scalar.string;
 
+import org.elasticsearch.xpack.eql.EqlTestUtils;
 import org.elasticsearch.xpack.ql.expression.Expression;
 import org.elasticsearch.xpack.ql.expression.gen.pipeline.Pipe;
 import org.elasticsearch.xpack.ql.tree.AbstractNodeTestCase;
@@ -32,7 +33,11 @@ public class StringContainsFunctionPipeTests extends AbstractNodeTestCase<String
     }
     
     public static StringContainsFunctionPipe randomStringContainsFunctionPipe() {
-        return (StringContainsFunctionPipe) (new StringContains(randomSource(), randomStringLiteral(), randomStringLiteral()).makePipe());
+        return (StringContainsFunctionPipe) (new StringContains(randomSource(),
+                                    randomStringLiteral(),
+                                    randomStringLiteral(),
+                                    EqlTestUtils.randomConfiguration())
+            .makePipe());
     }
 
     @Override
@@ -45,7 +50,8 @@ public class StringContainsFunctionPipeTests extends AbstractNodeTestCase<String
                 b1.source(),
                 newExpression,
                 b1.string(),
-                b1.substring());
+                b1.substring(),
+                b1.isCaseSensitive());
         assertEquals(newB, b1.transformPropertiesOnly(v -> Objects.equals(v, b1.expression()) ? newExpression : v, Expression.class));
         
         StringContainsFunctionPipe b2 = randomInstance();
@@ -54,7 +60,8 @@ public class StringContainsFunctionPipeTests extends AbstractNodeTestCase<String
                 newLoc,
                 b2.expression(),
                 b2.string(),
-                b2.substring());
+                b2.substring(),
+                b2.isCaseSensitive());
         assertEquals(newB,
                 b2.transformPropertiesOnly(v -> Objects.equals(v, b2.source()) ? newLoc : v, Source.class));
     }
@@ -64,8 +71,9 @@ public class StringContainsFunctionPipeTests extends AbstractNodeTestCase<String
         StringContainsFunctionPipe b = randomInstance();
         Pipe newString = pipe(((Expression) randomValueOtherThan(b.string(), () -> randomStringLiteral())));
         Pipe newSubstring = pipe(((Expression) randomValueOtherThan(b.substring(), () -> randomStringLiteral())));
+        boolean newCaseSensitive = randomValueOtherThan(b.isCaseSensitive(), () -> randomBoolean());
         StringContainsFunctionPipe newB =
-                new StringContainsFunctionPipe(b.source(), b.expression(), b.string(), b.substring());
+                new StringContainsFunctionPipe(b.source(), b.expression(), b.string(), b.substring(), newCaseSensitive);
         
         StringContainsFunctionPipe transformed = newB.replaceChildren(newString, b.substring());
         assertEquals(transformed.string(), newString);
@@ -92,15 +100,18 @@ public class StringContainsFunctionPipeTests extends AbstractNodeTestCase<String
         randoms.add(f -> new StringContainsFunctionPipe(f.source(),
                 f.expression(),
                 pipe(((Expression) randomValueOtherThan(f.string(), () -> randomStringLiteral()))),
-                f.substring()));
+                f.substring(),
+                randomValueOtherThan(f.isCaseSensitive(), () -> randomBoolean())));
         randoms.add(f -> new StringContainsFunctionPipe(f.source(),
                 f.expression(),
                 f.string(),
-                pipe(((Expression) randomValueOtherThan(f.substring(), () -> randomStringLiteral())))));
+                pipe(((Expression) randomValueOtherThan(f.substring(), () -> randomStringLiteral()))),
+                randomValueOtherThan(f.isCaseSensitive(), () -> randomBoolean())));
         randoms.add(f -> new StringContainsFunctionPipe(f.source(),
                 f.expression(),
                 pipe(((Expression) randomValueOtherThan(f.string(), () -> randomStringLiteral()))),
-                pipe(((Expression) randomValueOtherThan(f.substring(), () -> randomStringLiteral())))));
+                pipe(((Expression) randomValueOtherThan(f.substring(), () -> randomStringLiteral()))),
+                randomValueOtherThan(f.isCaseSensitive(), () -> randomBoolean())));
         
         return randomFrom(randoms).apply(instance);
     }
@@ -110,6 +121,7 @@ public class StringContainsFunctionPipeTests extends AbstractNodeTestCase<String
         return new StringContainsFunctionPipe(instance.source(),
                 instance.expression(),
                 instance.string(),
-                instance.substring());
+                instance.substring(),
+                instance.isCaseSensitive());
     }
 }

x-pack/plugin/eql/src/test/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringContainsFunctionProcessorTests.java

@@ -8,10 +8,11 @@ package org.elasticsearch.xpack.eql.expression.function.scalar.string;
 
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xpack.eql.EqlIllegalArgumentException;
-import org.elasticsearch.xpack.eql.expression.function.scalar.string.StringContainsFunctionProcessor;
 
+import java.util.Locale;
 import java.util.concurrent.Callable;
 
+import static org.elasticsearch.xpack.eql.expression.function.scalar.string.StringContainsFunctionProcessor.doProcess;
 import static org.hamcrest.Matchers.equalTo;
 
 public class StringContainsFunctionProcessorTests extends ESTestCase {
@@ -24,26 +25,36 @@ public class StringContainsFunctionProcessorTests extends ESTestCase {
         }
     }
 
-    public void testNullOrEmptyParameters() throws Exception {
+    public void testStringContains() throws Exception {
         run(() -> {
             String substring = randomBoolean() ? null : randomAlphaOfLength(10);
-            String str = randomBoolean() ? null : randomAlphaOfLength(10);
+            String str = randomBoolean() ? null : randomValueOtherThan(substring, () -> randomAlphaOfLength(10));
+            boolean caseSensitive = randomBoolean();
             if (str != null && substring != null) {
                 str += substring;
-                str += randomAlphaOfLength(10);
+                str += randomValueOtherThan(substring, () -> randomAlphaOfLength(10));
             }
             final String string = str;
 
             // The string parameter can be null. Expect exception if any of other parameters is null.
-            if ((string != null) && (substring == null)) {
+            if (string != null && substring == null) {
                 EqlIllegalArgumentException e = expectThrows(EqlIllegalArgumentException.class,
-                        () -> StringContainsFunctionProcessor.doProcess(string, substring));
+                        () -> doProcess(string, substring, caseSensitive));
                 assertThat(e.getMessage(), equalTo("A string/char is required; received [null]"));
             } else {
-                assertThat(StringContainsFunctionProcessor.doProcess(string, substring),
+                assertThat(doProcess(string, substring, caseSensitive), equalTo(string == null ? null : true));
-                        equalTo(string == null ? null : true));
+
+                // deliberately make the test return "false" by lowercasing or uppercasing the substring in a case-sensitive scenario
+                if (caseSensitive && substring != null) {
+                    String subsChanged = randomBoolean() ? substring.toLowerCase(Locale.ROOT) : substring.toUpperCase(Locale.ROOT);
+                    if (substring.equals(subsChanged) == false) {
+                        assertThat(doProcess(string, subsChanged, caseSensitive), equalTo(string == null ? null : false));
                     }
+                }
+            }
+
             return null;
         });
     }
+
 }

x-pack/plugin/eql/src/test/java/org/elasticsearch/xpack/eql/expression/function/scalar/string/StringUtilsTests.java

@@ -8,6 +8,8 @@ package org.elasticsearch.xpack.eql.expression.function.scalar.string;
 
 import org.elasticsearch.test.ESTestCase;
 
+import java.util.Locale;
+
 import static org.elasticsearch.xpack.eql.expression.function.scalar.string.StringUtils.stringContains;
 import static org.elasticsearch.xpack.eql.expression.function.scalar.string.StringUtils.substringSlice;
 import static org.elasticsearch.xpack.ql.util.StringUtils.EMPTY;
@@ -140,14 +142,36 @@ public class StringUtilsTests extends ESTestCase {
     }
 
     public void testStringContainsWithNullOrEmpty() {
-        assertFalse(stringContains(null, null));
+        assertFalse(stringContains(null, null, true));
-        assertFalse(stringContains(null, ""));
+        assertFalse(stringContains(null, "", true));
-        assertFalse(stringContains("", null));
+        assertFalse(stringContains("", null, true));
+
+        assertFalse(stringContains(null, null, false));
+        assertFalse(stringContains(null, "", false));
+        assertFalse(stringContains("", null, false));
     }
 
-    public void testStringContainsWithRandom() throws Exception {
+    public void testStringContainsWithRandomCaseSensitive() throws Exception {
         String substring = randomAlphaOfLength(10);
-        String string = randomAlphaOfLength(10) + substring + randomAlphaOfLength(10);
+        String string = randomValueOtherThan(substring, () -> randomAlphaOfLength(10))
-        assertTrue(stringContains(string, substring));
+            + substring
+            + randomValueOtherThan(substring, () -> randomAlphaOfLength(10));
+        assertTrue(stringContains(string, substring, true));
+    }
+
+    public void testStringContainsWithRandomCaseInsensitive() throws Exception {
+        String substring = randomAlphaOfLength(10);
+        String subsChanged = substring.toUpperCase(Locale.ROOT);
+        String string = randomValueOtherThan(subsChanged, () -> randomAlphaOfLength(10))
+            + subsChanged
+            + randomValueOtherThan(subsChanged, () -> randomAlphaOfLength(10));
+        assertTrue(stringContains(string, substring, false));
+
+        substring = randomAlphaOfLength(10);
+        subsChanged = substring.toLowerCase(Locale.ROOT);
+        string = randomValueOtherThan(subsChanged, () -> randomAlphaOfLength(10))
+            + subsChanged
+            + randomValueOtherThan(subsChanged, () -> randomAlphaOfLength(10));
+        assertTrue(stringContains(string, substring, false));
     }
 }

x-pack/plugin/eql/src/test/resources/queryfolder_tests.txt

@@ -189,14 +189,23 @@ process where startsWith(user_name, 'A') or startsWith(user_name, 'B')
 {"prefix":{"user_name":{"value":"B","boost":1.0}}}],"adjust_pure_negative":true,"boost":1.0}}]
 ;
 
-stringContains
+stringContains-caseSensitive
 process where stringContains(process_name, "foo")
 ;
 "script":{"source":"InternalQlScriptUtils.nullSafeFilter(InternalEqlScriptUtils.stringContains(
-InternalQlScriptUtils.docValue(doc,params.v0),params.v1))"
+InternalQlScriptUtils.docValue(doc,params.v0),params.v1,params.v2))"
-"params":{"v0":"process_name","v1":"foo"}
+"params":{"v0":"process_name","v1":"foo","v2":true}
 ;
 
+stringContains-caseInsensitive
+process where stringContains(process_name, "foo")
+;
+"script":{"source":"InternalQlScriptUtils.nullSafeFilter(InternalEqlScriptUtils.stringContains(
+InternalQlScriptUtils.docValue(doc,params.v0),params.v1,params.v2))"
+"params":{"v0":"process_name","v1":"foo","v2":false}
+;
+
+
 stringFunction
 process where string(pid) == "123"
 ;