refactor: extract AbstractPythonAntlrDetector, fix MD5 hotspot, boost coverage to 90.6%

.claude/settings.local.json

@@ -1,4 +1,9 @@
 {
+  "spinnerTipsEnabled": false,
   "prefersReducedMotion": true,
-  "spinnerTipsEnabled": false
+  "permissions": {
+    "allow": [
+      "Bash(rtk gain:*)"
+    ]
+  }
 }

src/main/java/io/github/randomcodespace/iq/cache/FileHasher.java

@@ -9,25 +9,23 @@
 import java.util.HexFormat;
 
 /**
- * Computes MD5 hash of file content for change detection.
- * MD5 is used because it is fast and sufficient for content-change
- * detection (not for cryptographic purposes).
+ * Computes SHA-256 hash of file content for change detection.
  */
 public final class FileHasher {
 
     private FileHasher() {
     }
 
     /**
-     * Compute the MD5 hex digest of a file's content.
+     * Compute the SHA-256 hex digest of a file's content.
      *
      * @param file path to the file
-     * @return lowercase hex MD5 hash string
+     * @return lowercase hex SHA-256 hash string
      * @throws IOException if the file cannot be read
      */
     public static String hash(Path file) throws IOException {
         try {
-            MessageDigest md = MessageDigest.getInstance("MD5");
+            MessageDigest md = MessageDigest.getInstance("SHA-256");
             byte[] buf = new byte[8192];
             try (InputStream is = Files.newInputStream(file)) {
                 int n;
@@ -37,23 +35,23 @@
             }
             return HexFormat.of().formatHex(md.digest());
         } catch (NoSuchAlgorithmException e) {
-            throw new RuntimeException("MD5 not available", e);
+            throw new RuntimeException("SHA-256 not available", e);
         }
     }
 
     /**
-     * Compute the MD5 hex digest of a string's content (UTF-8 bytes).
+     * Compute the SHA-256 hex digest of a string's content (UTF-8 bytes).
      *
      * @param content the string to hash
-     * @return lowercase hex MD5 hash string
+     * @return lowercase hex SHA-256 hash string
      */
     public static String hashString(String content) {
         try {
-            MessageDigest md = MessageDigest.getInstance("MD5");
+            MessageDigest md = MessageDigest.getInstance("SHA-256");
             md.update(content.getBytes(java.nio.charset.StandardCharsets.UTF_8));
             return HexFormat.of().formatHex(md.digest());
         } catch (NoSuchAlgorithmException e) {
-            throw new RuntimeException("MD5 not available", e);
+            throw new RuntimeException("SHA-256 not available", e);
         }
     }
 }

src/main/java/io/github/randomcodespace/iq/detector/python/AbstractPythonAntlrDetector.java

@@ -0,0 +1,65 @@
+package io.github.randomcodespace.iq.detector.python;
+
+import io.github.randomcodespace.iq.detector.AbstractAntlrDetector;
+import io.github.randomcodespace.iq.detector.DetectorContext;
+import io.github.randomcodespace.iq.grammar.AntlrParserFactory;
+import io.github.randomcodespace.iq.grammar.python.Python3Parser;
+import org.antlr.v4.runtime.tree.ParseTree;
+
+import java.util.Set;
+import java.util.regex.Pattern;
+
+/**
+ * Abstract base for Python ANTLR-based detectors.
+ * Provides shared {@link #parse(DetectorContext)} with large-file regex fallback,
+ * language support declaration, and Python-specific AST helpers used across
+ * multiple Python detectors.
+ */
+public abstract class AbstractPythonAntlrDetector extends AbstractAntlrDetector {
+
+    /** Matches the start of the next class definition — used to bound class bodies in regex fallback. */
+    protected static final Pattern NEXT_CLASS_RE = Pattern.compile("\\nclass\\s+\\w+");
+
+    @Override
+    public Set<String> getSupportedLanguages() {
+        return Set.of("python");
+    }
+
+    @Override
+    protected ParseTree parse(DetectorContext ctx) {
+        // Skip ANTLR for very large files (>500KB) — regex fallback is faster
+        if (ctx.content().length() > 500_000) {
+            return null;
+        }
+        return AntlrParserFactory.parse("python", ctx.content());
+    }
+
+    /**
+     * Build a comma-separated string of base class names from an ANTLR class definition context.
+     *
+     * @param classCtx the parsed class definition
+     * @return base class text, or null if no base classes
+     */
+    protected static String getBaseClassesText(Python3Parser.ClassdefContext classCtx) {
+        if (classCtx.arglist() == null) return null;
+        StringBuilder sb = new StringBuilder();
+        for (var arg : classCtx.arglist().argument()) {
+            if (sb.length() > 0) sb.append(", ");
+            sb.append(arg.getText());
+        }
+        return sb.toString();
+    }
+
+    /**
+     * Extract the source text of an entire class body using ANTLR token positions.
+     *
+     * @param text     full source content
+     * @param classCtx the parsed class definition
+     * @return substring covering the full class body
+     */
+    protected static String extractClassBody(String text, Python3Parser.ClassdefContext classCtx) {
+        int start = classCtx.getStart().getStartIndex();
+        int stop = classCtx.getStop() != null ? classCtx.getStop().getStopIndex() + 1 : text.length();
+        return text.substring(Math.min(start, text.length()), Math.min(stop, text.length()));
+    }
+}

src/main/java/io/github/randomcodespace/iq/detector/python/AbstractPythonDbDetector.java

@@ -0,0 +1,71 @@
+package io.github.randomcodespace.iq.detector.python;
+
+import io.github.randomcodespace.iq.analyzer.InfraEndpoint;
+import io.github.randomcodespace.iq.analyzer.InfrastructureRegistry;
+import io.github.randomcodespace.iq.model.CodeEdge;
+import io.github.randomcodespace.iq.model.CodeNode;
+import io.github.randomcodespace.iq.model.EdgeKind;
+import io.github.randomcodespace.iq.model.NodeKind;
+
+import java.util.List;
+
+/**
+ * Abstract base for Python ORM detectors that emit DATABASE_CONNECTION nodes and CONNECTS_TO edges.
+ * Extends {@link AbstractPythonAntlrDetector} with shared database node/edge helpers
+ * used by Django and SQLAlchemy detectors.
+ */
+public abstract class AbstractPythonDbDetector extends AbstractPythonAntlrDetector {
+
+    /**
+     * Ensure a DATABASE_CONNECTION node exists in the result, creating it if needed.
+     * Uses the first database from the InfrastructureRegistry if available,
+     * otherwise creates a generic "database:unknown" node.
+     *
+     * @param registry infrastructure registry (may be null)
+     * @param nodes    the nodes list to add the DB node to if missing
+     * @return the database node ID
+     */
+    protected static String ensureDbNode(InfrastructureRegistry registry, List<CodeNode> nodes) {
+        String dbNodeId;
+        if (registry != null && !registry.getDatabases().isEmpty()) {
+            InfraEndpoint db = registry.getDatabases().values().iterator().next();
+            dbNodeId = "infra:" + db.id();
+            if (nodes.stream().noneMatch(n -> dbNodeId.equals(n.getId()))) {
+                CodeNode dbNode = new CodeNode(dbNodeId, NodeKind.DATABASE_CONNECTION,
+                        db.name() + " (" + db.type() + ")");
+                dbNode.getProperties().put("type", db.type());
+                if (db.connectionUrl() != null) dbNode.getProperties().put("url", db.connectionUrl());
+                nodes.add(dbNode);
+            }
+        } else {
+            dbNodeId = "database:unknown";
+            if (nodes.stream().noneMatch(n -> dbNodeId.equals(n.getId()))) {
+                nodes.add(new CodeNode(dbNodeId, NodeKind.DATABASE_CONNECTION, "Database"));
+            }
+        }
+        return dbNodeId;
+    }
+
+    /**
+     * Add a CONNECTS_TO edge from the given source node to the database node.
+     *
+     * @param sourceId the source node ID
+     * @param registry infrastructure registry (may be null)
+     * @param nodes    the nodes list (used to find/create the DB node)
+     * @param edges    the edges list to add the edge to
+     */
+    protected static void addDbEdge(String sourceId, InfrastructureRegistry registry,
+            List<CodeNode> nodes, List<CodeEdge> edges) {
+        String dbNodeId = ensureDbNode(registry, nodes);
+        CodeNode targetRef = nodes.stream()
+                .filter(n -> dbNodeId.equals(n.getId()))
+                .findFirst()
+                .orElseGet(() -> new CodeNode(dbNodeId, NodeKind.DATABASE_CONNECTION, "Database"));
+        CodeEdge edge = new CodeEdge();
+        edge.setId(sourceId + "->connects_to->" + dbNodeId);
+        edge.setKind(EdgeKind.CONNECTS_TO);
+        edge.setSourceId(sourceId);
+        edge.setTarget(targetRef);
+        edges.add(edge);
+    }
+}

src/main/java/io/github/randomcodespace/iq/detector/python/CeleryTaskDetector.java

@@ -1,9 +1,7 @@
 package io.github.randomcodespace.iq.detector.python;
 
-import io.github.randomcodespace.iq.detector.AbstractAntlrDetector;
 import io.github.randomcodespace.iq.detector.DetectorContext;
 import io.github.randomcodespace.iq.detector.DetectorResult;
-import io.github.randomcodespace.iq.grammar.AntlrParserFactory;
 import io.github.randomcodespace.iq.grammar.python.Python3Parser;
 import io.github.randomcodespace.iq.grammar.python.Python3ParserBaseListener;
 import io.github.randomcodespace.iq.model.CodeEdge;
@@ -33,7 +31,7 @@
     properties = {"broker", "task_name"}
 )
 @Component
-public class CeleryTaskDetector extends AbstractAntlrDetector {
+public class CeleryTaskDetector extends AbstractPythonAntlrDetector {
 
     // --- Regex patterns ---
     private static final Pattern TASK_DECORATOR = Pattern.compile(
@@ -56,20 +54,6 @@ public String getName() {
         return "python.celery_tasks";
     }
 
-    @Override
-    public Set<String> getSupportedLanguages() {
-        return Set.of("python");
-    }
-
-    @Override
-    protected ParseTree parse(DetectorContext ctx) {
-        // Skip ANTLR for very large files (>500KB) — regex fallback is faster
-        if (ctx.content().length() > 500_000) {
-            return null; // triggers regex fallback
-        }
-        return AntlrParserFactory.parse("python", ctx.content());
-    }
-
     @Override
     protected DetectorResult detectWithAst(ParseTree tree, DetectorContext ctx) {
         List<CodeNode> nodes = new ArrayList<>();

src/main/java/io/github/randomcodespace/iq/detector/python/DjangoAuthDetector.java

@@ -1,9 +1,7 @@
 package io.github.randomcodespace.iq.detector.python;
 
-import io.github.randomcodespace.iq.detector.AbstractAntlrDetector;
 import io.github.randomcodespace.iq.detector.DetectorContext;
 import io.github.randomcodespace.iq.detector.DetectorResult;
-import io.github.randomcodespace.iq.grammar.AntlrParserFactory;
 import io.github.randomcodespace.iq.grammar.python.Python3Parser;
 import io.github.randomcodespace.iq.grammar.python.Python3ParserBaseListener;
 import io.github.randomcodespace.iq.model.CodeNode;
@@ -15,7 +13,6 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import io.github.randomcodespace.iq.detector.DetectorInfo;
@@ -31,7 +28,7 @@
     properties = {"auth_type", "permissions"}
 )
 @Component
-public class DjangoAuthDetector extends AbstractAntlrDetector {
+public class DjangoAuthDetector extends AbstractPythonAntlrDetector {
 
     // --- Regex fallback patterns ---
     private static final Pattern LOGIN_REQUIRED_RE = Pattern.compile("@login_required\\b");
@@ -56,20 +53,6 @@ public String getName() {
         return "django_auth";
     }
 
-    @Override
-    public Set<String> getSupportedLanguages() {
-        return Set.of("python");
-    }
-
-    @Override
-    protected ParseTree parse(DetectorContext ctx) {
-        // Skip ANTLR for very large files (>500KB) — regex fallback is faster
-        if (ctx.content().length() > 500_000) {
-            return null; // triggers regex fallback
-        }
-        return AntlrParserFactory.parse("python", ctx.content());
-    }
-
     @Override
     protected DetectorResult detectWithAst(ParseTree tree, DetectorContext ctx) {
         List<CodeNode> nodes = new ArrayList<>();