👻 improve logic / structure a bit

Signed-off-by: Pranav Gaikwad <[email protected]>

java-analyzer-bundle.core/src/main/java/io/konveyor/tackle/core/internal/symbol/ConstructorCallSymbolProvider.java

@@ -48,31 +48,11 @@ public List<SymbolInformation> get(SearchMatch match) throws CoreException {
                 astParser.setSource(unit);
                 astParser.setResolveBindings(true);
                 CompilationUnit cu = (CompilationUnit) astParser.createAST(null);
-                cu.accept(new ASTVisitor() {
-                    // we are only doing this for MethodInvocation right now
-                    // look into MethodDeclaration if needed
-                    public boolean visit(MethodInvocation node) {
-                        try {
-                            IMethodBinding binding = node.resolveMethodBinding();
-                            if (binding != null) {
-                                // get fqn of the method being called
-                                ITypeBinding declaringClass = binding.getDeclaringClass();
-                                if (declaringClass != null) {
-                                    String fullyQualifiedName = declaringClass.getQualifiedName() + "." + binding.getName();
-                                    // match fqn with query pattern
-                                    if (fullyQualifiedName.matches(getCleanedQuery(query))) {
-                                        symbols.add(symbol);
-                                    } else {
-                                        logInfo("fqn " + fullyQualifiedName + " did not match with " + query);
-                                    }
-                                }
-                            } 
-                        } catch (Exception e) {
-                            logInfo("error determining accuracy of match: " + e);
-                        }
-                        return true;
-                    }
-                });
+                CustomASTVisitor visitor = new CustomASTVisitor(query, match);
+                cu.accept(visitor);
+                if (visitor.symbolMatches()) {
+                    symbols.add(symbol);
+                }
             } else {
                 symbols.add(symbol);
             }

java-analyzer-bundle.core/src/main/java/io/konveyor/tackle/core/internal/symbol/CustomASTVisitor.java

@@ -0,0 +1,86 @@
+package io.konveyor.tackle.core.internal.symbol;
+
+import org.eclipse.jdt.core.dom.ASTVisitor;
+import org.eclipse.jdt.core.dom.ASTNode;
+import org.eclipse.jdt.core.dom.IMethodBinding;
+import org.eclipse.jdt.core.dom.ITypeBinding;
+import org.eclipse.jdt.core.dom.MethodInvocation;
+import org.eclipse.jdt.core.search.SearchMatch;
+
+import static org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin.logInfo;
+
+public class CustomASTVisitor extends ASTVisitor {
+    private String query;
+    private SearchMatch match;
+    private boolean symbolMatches;
+
+
+    public CustomASTVisitor(String query, SearchMatch match) {
+        /*
+         * When comparing query pattern with an actual java element's fqn
+         * we need to make sure that * not preceded with a . are replaced
+         * by .* so that java regex works as expected on them
+        */
+        this.query = query.replaceAll("(?<!\\.)\\*", ".*");
+        this.symbolMatches = false;
+        this.match = match;
+    }
+
+    /*
+     * When visiting AST nodes, it may happen that we visit more nodes
+     * than needed. We need to ensure that we are only visiting ones
+     * that are found in the given search match. I wrote this for methods
+     * where I observed that a node starts at the beginning of line whereas match
+     * starts at an offset within that line. However, both end on the same position.
+     * This could differ for other locations. In that case, change logic based
+     * on type of the node you get.
+     */
+    private boolean shouldVisit(ASTNode node) {
+        return (this.match.getOffset() + this.match.getLength()) == 
+            (node.getStartPosition() + node.getLength());
+    }
+
+    /* 
+     * This is to get information from a MethodInvocation
+     * used for METHOD_CALL and CONSTRUCTOR_CALL matches
+     * we only discard a match only when we can tell for sure
+     * returning false stops further visits
+    */
+    @Override
+    public boolean visit(MethodInvocation node) {
+        try {
+            if (!this.shouldVisit(node)) {
+                return true;
+            }
+            IMethodBinding binding = node.resolveMethodBinding();
+            if (binding != null) {
+                // get fqn of the method being called
+                ITypeBinding declaringClass = binding.getDeclaringClass();
+                if (declaringClass != null) {
+                    String fullyQualifiedName = declaringClass.getQualifiedName() + "." + binding.getName();
+                    // match fqn with query pattern
+                    if (fullyQualifiedName.matches(this.query)) {
+                        this.symbolMatches = true;
+                        return false;
+                    } else {
+                        logInfo("method fqn " + fullyQualifiedName + " did not match with " + query);
+                        return true;
+                    }
+                }
+            } 
+            // sometimes binding or declaring class cannot be found, usually due to errors
+            // in source code. in that case, we will fallback and accept the match
+            this.symbolMatches = true;
+            return false;
+        } catch (Exception e) {
+            logInfo("error visiting MethodInvocation node: " + e);
+            // this is so that we fallback to old approach and we dont lose a result
+            this.symbolMatches = true;
+            return false;
+        }
+    }
+
+    public boolean symbolMatches() {
+        return this.symbolMatches;
+    }
+}

java-analyzer-bundle.core/src/main/java/io/konveyor/tackle/core/internal/symbol/MethodCallSymbolProvider.java

@@ -44,31 +44,11 @@ public List<SymbolInformation> get(SearchMatch match) {
                 astParser.setSource(unit);
                 astParser.setResolveBindings(true);
                 CompilationUnit cu = (CompilationUnit) astParser.createAST(null);
-                cu.accept(new ASTVisitor() {
-                    // we are only doing this for MethodInvocation right now
-                    // look into MethodDeclaration if needed
-                    public boolean visit(MethodInvocation node) {
-                        try {
-                            IMethodBinding binding = node.resolveMethodBinding();
-                            if (binding != null) {
-                                // get fqn of the method being called
-                                ITypeBinding declaringClass = binding.getDeclaringClass();
-                                if (declaringClass != null) {
-                                    String fullyQualifiedName = declaringClass.getQualifiedName() + "." + binding.getName();
-                                    // match fqn with query pattern
-                                    if (fullyQualifiedName.matches(getCleanedQuery(query))) {
-                                        symbols.add(symbol);
-                                    } else {
-                                        logInfo("fqn " + fullyQualifiedName + " did not match with " + query);
-                                    }
-                                }
-                            } 
-                        } catch (Exception e) {
-                            logInfo("error determining accuracy of match: " + e);
-                        }
-                        return true;
-                    }
-                });
+                CustomASTVisitor visitor = new CustomASTVisitor(query, match);
+                cu.accept(visitor);
+                if (visitor.symbolMatches()) {
+                    symbols.add(symbol);
+                }
             } else {
                 symbols.add(symbol);
             }

java-analyzer-bundle.core/src/main/java/io/konveyor/tackle/core/internal/symbol/SymbolProvider.java

@@ -167,13 +167,4 @@ private static void setPosition(Position position, int[] coords) {
 		position.setLine(coords[0]);
 		position.setCharacter(coords[1]);
 	}
-
-    /*
-     * When comparing query pattern with an actual found java element's fqn
-     * we need to make sure that * that are not preceded with a . are replaced
-     * by .* so that java regex works as expected on them
-     */
-    default String getCleanedQuery(String query) {
-        return query.replaceAll("(?<!\\.)\\*", ".*");
-    }
 }