feat: support for Java.InputMismatchException

error_templates/java/input_mismatch_exception.go

@@ -0,0 +1,109 @@
+package java
+
+import (
+	"fmt"
+
+	lib "github.com/nedpals/errgoengine"
+	sitter "github.com/smacker/go-tree-sitter"
+)
+
+var scannerMethodsToTypes = map[string]string{
+	"nextInt":    "integer",
+	"nextLong":   "long",
+	"nextByte":   "byte",
+	"nextChar":   "character",
+	"nextDouble": "double",
+	"nextFloat":  "float",
+	"nextShort":  "short",
+}
+
+var InputMismatchException = lib.ErrorTemplate{
+	Name:    "InputMismatchException",
+	Pattern: runtimeErrorPattern("java.util.InputMismatchException", ""),
+	OnAnalyzeErrorFn: func(cd *lib.ContextData, m *lib.MainError) {
+		query := "(method_invocation object: (_) name: (identifier) @fn-name arguments: (argument_list) (#eq? @fn-name \"nextInt\"))"
+		for q := m.Nearest.Query(query); q.Next(); {
+			if q.CurrentTagName() != "fn-name" {
+				continue
+			}
+
+			node := q.CurrentNode()
+			m.Nearest = node
+		}
+	},
+	OnGenExplainFn: func(cd *lib.ContextData, gen *lib.ExplainGenerator) {
+		methodName := cd.MainError.Nearest.Text()
+		expectedType := scannerMethodsToTypes[methodName]
+		gen.Add(
+			"This error occurs when a non-%s input is passed to the `%s()` method of the `Scanner` class.",
+			expectedType,
+			methodName)
+	},
+	OnGenBugFixFn: func(cd *lib.ContextData, gen *lib.BugFixGenerator) {
+		// get nearest block from position
+		cursor := sitter.NewTreeCursor(cd.MainError.Document.RootNode().Node)
+		rawNearestBlock := nearestNodeFromPosByType(cursor, "block", cd.MainError.Nearest.StartPosition())
+
+		if rawNearestBlock != nil && !rawNearestBlock.IsNull() {
+			nearestBlock := lib.WrapNode(cd.MainError.Document, rawNearestBlock)
+
+			gen.Add("Add a try-catch for error handling", func(s *lib.BugFixSuggestion) {
+				step := s.AddStep("Implement error handling to account for input mismatches and prompt the user for valid input.")
+
+				wrapStatement(
+					step,
+					"try {",
+					"} catch (InputMismatchException e) {\n\t<i>System.out.println(\"Invalid input. Please try again.\");\n\t}",
+					lib.Location{
+						StartPos: lib.Position{
+							Line: nearestBlock.FirstNamedChild().StartPosition().Line,
+						},
+						EndPos: nearestBlock.LastNamedChild().EndPosition(),
+					},
+					true,
+				)
+			})
+		}
+	},
+}
+
+func nearestNodeFromPosByType(cursor *sitter.TreeCursor, expType string, pos lib.Position) *sitter.Node {
+	cursor.GoToFirstChild()
+	defer cursor.GoToParent()
+
+	var nearest *sitter.Node
+
+	for {
+		currentNode := cursor.CurrentNode()
+		pointA := currentNode.StartPoint()
+		pointB := currentNode.EndPoint()
+
+		fmt.Println(currentNode.Type(), currentNode.StartByte())
+
+		// stop if node is above the position
+		if uint32(pos.Line) < pointA.Row+1 {
+			break
+		}
+
+		// check if the current node is the nearest
+		if currentNode.Type() == expType && uint32(pos.Line) >= pointA.Row+1 && uint32(pos.Line) <= pointB.Row+1 {
+			nearest = currentNode
+		}
+
+		if currentNode.ChildCount() != 0 && uint32(pos.Line) >= pointA.Row+1 && uint32(pos.Line) <= pointB.Row+1 {
+			nearestFromInner := nearestNodeFromPosByType(cursor, expType, pos)
+			// check if the nearest from the inner nodes is nearer than the current nearest
+			if nearestFromInner != nil && !nearestFromInner.IsNull() {
+				nearest = nearestFromInner
+			}
+		}
+
+		if !cursor.GoToNextSibling() {
+			break
+		}
+
+		fmt.Println("next")
+	}
+
+	return nearest
+}

error_templates/java/java.go

@@ -19,6 +19,7 @@ func LoadErrorTemplates(errorTemplates *lib.ErrorTemplates) {
 	errorTemplates.MustAdd(java.Language, StringIndexOutOfBoundsException)
 	errorTemplates.MustAdd(java.Language, NoSuchElementException)
 	errorTemplates.MustAdd(java.Language, NumberFormatException)
+	errorTemplates.MustAdd(java.Language, InputMismatchException)
 
 	// Compile time
 	errorTemplates.MustAdd(java.Language, PublicClassFilenameMismatchError)

error_templates/java/test_files/input_mismatch_exception/Main.java

@@ -0,0 +1,10 @@
+import java.util.Scanner;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        System.out.print("Enter an integer: ");
+        int number = scanner.nextInt(); // Error: InputMismatchException for non-integer input
+        System.out.println("You entered: " + number);
+    }
+}

error_templates/java/test_files/input_mismatch_exception/test.txt

@@ -0,0 +1,41 @@
+template: "Java.InputMismatchException"
+---
+Exception in thread "main" java.util.InputMismatchException
+	at java.base/java.util.Scanner.throwFor(Scanner.java:947)
+	at java.base/java.util.Scanner.next(Scanner.java:1602)
+	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
+	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
+	at Main.main(Main.java:7)
+===
+template: "Java.InputMismatchException"
+---
+# InputMismatchException
+This error occurs when a non-integer input is passed to the `nextInt()` method of the `Scanner` class.
+```
+        System.out.print("Enter an integer: ");
+        int number = scanner.nextInt(); // Error: InputMismatchException for non-integer input
+                             ^^^^^^^
+        System.out.println("You entered: " + number);
+    }
+```
+## Steps to fix
+### Add a try-catch for error handling
+Implement error handling to account for input mismatches and prompt the user for valid input.
+```diff
+public class Main {
+    public static void main(String[] args) {
+-         Scanner scanner = new Scanner(System.in);
+-         System.out.print("Enter an integer: ");
+-         int number = scanner.nextInt(); // Error: InputMismatchException for non-integer input
+-         System.out.println("You entered: " + number);
++         try {
++             Scanner scanner = new Scanner(System.in);
++         System.out.print("Enter an integer: ");
++         int number = scanner.nextInt(); // Error: InputMismatchException for non-integer input
++         System.out.println("You entered: " + number);
++ } catch (InputMismatchException e) {
++             System.out.println("Invalid input. Please try again.");
++         }
+    }
+}
+```