refactoring/raise-code-coverage

doc/changes/changes_0.6.20.md

@@ -0,0 +1,14 @@
+# Udf Debugging Java 0.6.20, released 2026-07-16
+
+Code name: Code Coverage > 80%
+
+## Summary
+
+In this release we fixed Sonar findings and raised the code coverage ot over 80%.
+
+We added an integration test for `PushDownTesting`.
+
+## Features
+
+* Fixed Sonar findings and raised test coverage. (PR #86)
+

pom.xml

@@ -2,7 +2,7 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>udf-debugging-java</artifactId>
-    <version>0.6.19</version>
+    <version>0.6.20</version>
     <name>udf-debugging-java</name>
     <description>Utilities for debugging, profiling and code coverage measure for UDFs.</description>
     <url>https://github.com/exasol/udf-debugging-java/</url>
@@ -147,7 +147,7 @@
     <parent>
         <artifactId>udf-debugging-java-generated-parent</artifactId>
         <groupId>com.exasol</groupId>
-        <version>0.6.19</version>
+        <version>0.6.20</version>
         <relativePath>pk_generated_parent.pom</relativePath>
     </parent>
 </project>

src/main/java/com/exasol/udfdebugging/PushDownTesting.java

@@ -21,9 +21,10 @@ private PushDownTesting() {
      * @return generated push down query
      * @throws SQLException if execution fails
      */
+    @SuppressWarnings("java:S2077") // Constructed SQL only used in tests.
     public static String getPushDownSql(final Statement statement, final String query) throws SQLException {
         try (final ResultSet pushDownSqlResult = statement
-                .executeQuery("SELECT PUSHDOWN_SQL FROM (EXPLAIN VIRTUAL " + query + ");")) {
+                .executeQuery("SELECT PUSHDOWN_SQL FROM (EXPLAIN VIRTUAL " + query + ")")) {
             pushDownSqlResult.next();
             return pushDownSqlResult.getString("PUSHDOWN_SQL");
         }
@@ -37,10 +38,11 @@ public static String getPushDownSql(final Statement statement, final String quer
      * @return selection (where clause)
      * @throws SQLException if SQL statement fails
      */
+    @SuppressWarnings("java:S2077") // Constructed SQL only used in tests.
     public static String getSelectionThatIsSentToTheAdapter(final Statement statement, final String query)
             throws SQLException {
         try (final ResultSet pushDownSqlResult = statement
-                .executeQuery("SELECT PUSHDOWN_JSON FROM (EXPLAIN VIRTUAL " + query + ");")) {
+                .executeQuery("SELECT PUSHDOWN_JSON FROM (EXPLAIN VIRTUAL " + query + ")")) {
             pushDownSqlResult.next();
             final String pushdownJson = pushDownSqlResult.getString("PUSHDOWN_JSON");
             try (final JsonReader reader = Json.createReader(new StringReader(pushdownJson))) {

src/test/java/com/exasol/udfdebugging/PushDownTestingIT.java

@@ -0,0 +1,69 @@
+package com.exasol.udfdebugging;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+import org.junit.jupiter.api.Test;
+
+import com.exasol.udfdebugging.modules.TestSetup;
+
+class PushDownTestingIT {
+    private static final String VS_SCHEMA = "VS_SCHEMA";
+    private static final String VS_ADAPTER = VS_SCHEMA + ".VS_ADAPTER";
+    private static final String VIRTUAL_SCHEMA_NAME = "TEST_VS";
+    private static final String TABLE_NAME = "THE_TABLE";
+
+    private static String loadAdapterScriptContent() {
+        try (InputStream adapterScriptStream = PushDownTestingIT.class.getClassLoader()
+                .getResourceAsStream("virtual_schema_stub.lua")) {
+            if (adapterScriptStream == null) {
+                throw new AssertionError("Failed to find adapter script resource on the classpath.");
+            }
+            return new String(adapterScriptStream.readAllBytes(), StandardCharsets.UTF_8);
+        } catch (IOException exception) {
+            throw new AssertionError("Failed to read adapter script resource.", exception);
+        }
+    }
+
+
+    @Test
+    void testGetPushDownSqlFromExplainVirtual() throws SQLException {
+        try (
+                final TestSetup testSetup = new TestSetup();
+                final Statement statement = testSetup.getConnection().createStatement()
+        ) {
+            createVirtualSchema(statement);
+            final String pushDownSql = PushDownTesting.getPushDownSql(statement,
+                    "SELECT THE_VALUE FROM " + VIRTUAL_SCHEMA_NAME + "." + TABLE_NAME);
+            assertThat(pushDownSql, equalTo("SELECT 'Hello VS!'"));
+        }
+    }
+
+    @Test
+    void testGetSelectionThatIsSentToTheAdapter() throws SQLException {
+        try (
+                final TestSetup testSetup = new TestSetup();
+                final Statement statement = testSetup.getConnection().createStatement()
+        ) {
+            createVirtualSchema(statement);
+            final String pushDownSql = PushDownTesting.getSelectionThatIsSentToTheAdapter(statement,
+                    "SELECT THE_VALUE FROM " + VIRTUAL_SCHEMA_NAME + "." + TABLE_NAME
+                            + " WHERE THE_VALUE = 'something'");
+            assertThat(pushDownSql, equalTo(TABLE_NAME +".THE_VALUE='something'"));
+        }
+    }
+
+    private void createVirtualSchema(final Statement statement) throws SQLException {
+        statement.execute("DROP SCHEMA IF EXISTS " + VS_SCHEMA + "CASCADE");
+        statement.execute("CREATE SCHEMA " + VS_SCHEMA);
+        statement.execute("CREATE TABLE ORIGIN_TABLE(THE_VALUE CHAR(9))");
+        statement.execute("CREATE LUA ADAPTER SCRIPT " + VS_ADAPTER + " AS\n" + loadAdapterScriptContent() + "\n/");
+        statement.execute("CREATE VIRTUAL SCHEMA " + VIRTUAL_SCHEMA_NAME + " USING " + VS_ADAPTER);
+    }
+}

src/test/resources/virtual_schema_stub.lua

@@ -0,0 +1,61 @@
+-- A minimal Lua virtual schema that allows testing VS interaction.
+local cjson = require("cjson");
+
+function report_schema()
+    return {
+        schemaMetadata = {
+            tables = {
+                {
+                    name = "THE_TABLE",
+                    columns = {
+                        {
+                            name = "THE_VALUE",
+                            dataType = {
+                                type = "CHAR",
+                                size = 9
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+end
+
+function report_capabilities()
+        return {
+            capabilities = { "SELECTLIST_PROJECTION", "FILTER_EXPRESSIONS", "FN_PRED_EQUAL", "LITERAL_STRING" }
+        }
+end
+
+function pushdown(request)
+    if (request.filter == nil) then
+        return {
+            type = "select",
+            sql = "SELECT 'Hello VS!'"
+        }
+    else
+        return {
+            type = "select",
+            sql = "SELECT 'Hello VS!' FROM VS_SCHEMA.ORIGIN_TABLE WHERE THE_VALUE = 'something'"
+        }
+    end
+end
+
+function adapter_call(request_as_json)
+    local request = cjson.decode(request_as_json)
+    local response;
+    if request.type == "createVirtualSchema" or request.type == "refresh" then
+        response = report_schema()
+    elseif request.type == "dropVirtualSchema" or request.type == "setProperties" then
+        response = {}
+    elseif request.type == "getCapabilities" then
+        response = report_capabilities()
+    elseif request.type == "pushdown" then
+        response =  pushdown(request.pushdownRequest)
+    else
+        error("Unsupported adapter request: " .. (request.type or "'nil'"))
+    end
+    response.type = request.type
+    return cjson.encode(response)
+end