Eval startup snippets explicitly

jjava-distro/pom.xml

@@ -39,6 +39,11 @@
             <artifactId>testcontainers</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

jjava-distro/src/main/java/org/dflib/jjava/distro/JJava.java

@@ -55,7 +55,6 @@ public static void main(String[] args) throws Exception {
                 .version((String) pomProps.getOrDefault("version", ""))
 
                 .extensionsEnabled(Env.extensionsEnabled())
-                .startupSnippets(Env.startupSnippets())
                 .compilerOpts(Env.compilerOpts())
                 .timeout(Env.timeout())
 
@@ -79,6 +78,9 @@ public static void main(String[] args) throws Exception {
         // process custom locations: expand JShell classpath, install extensions from those places (if enabled)
         kernel.addToClasspath(Env.extraClasspath());
 
+        // run user defined startup snippets explicitly after the default startup
+        Env.startupSnippets().forEach(kernel::evalRaw);
+
         // connect to Jupyter
         kernel.becomeHandlerForConnection(connection);
         connection.connect();

jjava-distro/src/test/java/org/dflib/jjava/distro/KernelStartupIT.java

@@ -3,9 +3,12 @@
 import org.junit.jupiter.api.Test;
 import org.testcontainers.containers.Container;
 
+import java.util.Map;
+
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.not;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.matchesPattern;
 
 public class KernelStartupIT extends ContainerizedKernelCase {
 
@@ -17,4 +20,17 @@ public void startUp() throws Exception {
         assertThat(snippetResult.getStderr(), not(containsString("|")));
         assertThat(snippetResult.getStdout(), containsString("1001.0"));
     }
+
+    @Test
+    void startUp_scriptRequiresClasspath() throws Exception {
+        Map<String, String> env = Map.of(
+                Env.JJAVA_CLASSPATH, TEST_CLASSPATH,
+                Env.JJAVA_STARTUP_SCRIPT, "var obj = new org.dflib.jjava.Dummy()"
+        );
+        String snippet = "\"hash = \" + obj.hashCode()";
+        Container.ExecResult snippetResult = executeInKernel(snippet, env);
+
+        assertThat(snippetResult.getStdout(), not(containsString("|")));
+        assertThat(snippetResult.getStdout(), matchesPattern("(?s).*hash = -?\\d+.*"));
+    }
 }

jjava-jupyter/pom.xml

@@ -39,7 +39,7 @@
         </dependency>
         <dependency>
             <groupId>org.hamcrest</groupId>
-            <artifactId>hamcrest-all</artifactId>
+            <artifactId>hamcrest</artifactId>
             <scope>test</scope>
         </dependency>
         <dependency>
@@ -49,4 +49,4 @@
         </dependency>
     </dependencies>
 
-</project>
+</project>

jjava-kernel/src/main/java/org/dflib/jjava/kernel/JavaKernelBuilder.java

@@ -82,7 +82,7 @@ protected JShell buildJShell(JJavaExecutionControlProvider jShellExecControlProv
     }
 
     protected CodeEvaluator buildCodeEvaluator(JShell jShell, JJavaExecutionControlProvider jShellExecControlProvider) {
-        return new CodeEvaluator(jShell, jShellExecControlProvider, jShellExecControlID, startupSnippets);
+        return new CodeEvaluator(jShell, jShellExecControlProvider, jShellExecControlID);
     }
 
     protected MagicParser buildMagicParser(MagicTranspiler transpiler) {

jjava-kernel/src/main/java/org/dflib/jjava/kernel/execution/CodeEvaluator.java

@@ -37,21 +37,16 @@ public class CodeEvaluator {
     private final JJavaExecutionControlProvider execControlProvider;
     private final String execControlID;
     private final SourceCodeAnalysis sourceAnalyzer;
-    private final List<String> startupSnippets;
-
-    private volatile boolean initialized;
 
     public CodeEvaluator(
             JShell shell,
             JJavaExecutionControlProvider execControlProvider,
-            String execControlID,
-            List<String> startupSnippets) {
+            String execControlID) {
 
         this.shell = shell;
         this.execControlProvider = execControlProvider;
         this.execControlID = execControlID;
         this.sourceAnalyzer = shell.sourceCodeAnalysis();
-        this.startupSnippets = startupSnippets;
     }
 
     private SourceCodeAnalysis.CompletionInfo analyzeCompletion(String source) {
@@ -129,35 +124,6 @@ protected Object evalSingle(String code) {
     }
 
     public Object eval(String code) {
-        initIfNeeded();
-        return doEval(code);
-    }
-
-    private void initIfNeeded() {
-
-        // TODO: should we even bother trying to avoid a race condition with locking? Does Jupyter guarantee serial
-        //  cell execution?
-        if (!initialized) {
-            synchronized (this) {
-                if (!initialized) {
-
-                    // Runs startup snippets in the shell to initialize the environment. The call is deferred until the
-                    // first user requested evaluation to cleanly return errors when they happen.
-
-                    for (String s : startupSnippets) {
-                        // call "doEval" to bypass "initIfNeeded" and avoid infinite recursion
-                        doEval(s);
-                    }
-
-                    startupSnippets.clear();
-                    initialized = true;
-                }
-            }
-        }
-    }
-
-
-    private Object doEval(String code) {
         Object lastEvalResult = null;
         SourceCodeAnalysis.CompletionInfo info = this.sourceAnalyzer.analyzeCompletion(code);
 

pom.xml

@@ -53,7 +53,7 @@
         <commons.logging.version>1.3.5</commons.logging.version>
 
         <junit5.version>5.11.2</junit5.version>
-        <hamcrest.version>1.3</hamcrest.version>
+        <hamcrest.version>3.0</hamcrest.version>
         <jimfs.version>1.3.0</jimfs.version>
         <testcontainers.version>1.21.3</testcontainers.version>
         <slf4j.version>2.0.17</slf4j.version>
@@ -131,7 +131,7 @@
             </dependency>
             <dependency>
                 <groupId>org.hamcrest</groupId>
-                <artifactId>hamcrest-all</artifactId>
+                <artifactId>hamcrest</artifactId>
                 <version>${hamcrest.version}</version>
             </dependency>
             <dependency>