refactor: simplify QueryNode usage; use iterator approach

error_templates/java/already_defined_error.go

@@ -24,30 +24,21 @@ var AlreadyDefinedError = lib.ErrorTemplate{
 		pos := m.ErrorNode.StartPos
 
 		// get the nearest class declaration first based on error location
-		lib.QueryNode(rootNode, strings.NewReader("(class_declaration) @class"), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				pointA := c.Node.StartPoint()
-				pointB := c.Node.EndPoint()
-				if uint32(pos.Line) >= pointA.Row+1 && uint32(pos.Line) <= pointB.Row+1 {
-					node := lib.WrapNode(m.Nearest.Doc, c.Node)
-					aCtx.NearestClass = node
-					return false
-				}
+		for q := rootNode.Query("(class_declaration) @class"); q.Next(); {
+			classNode := q.CurrentNode()
+			pointA := classNode.StartPoint()
+			pointB := classNode.EndPoint()
+			if uint32(pos.Line) >= pointA.Row+1 && uint32(pos.Line) <= pointB.Row+1 {
+				aCtx.NearestClass = classNode
+				break
 			}
-			return true
-		})
+		}
 
 		// get the nearest method declaration based on symbol signature
-		lib.QueryNode(aCtx.NearestClass, strings.NewReader(rawQuery), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				node := lib.WrapNode(m.Nearest.Doc, c.Node)
-				aCtx.NearestMethod = node
-				return false
-			}
-			return true
-		})
+		for q := aCtx.NearestClass.Query(rawQuery); q.Next(); {
+			aCtx.NearestMethod = q.CurrentNode()
+			break
+		}
 
 		m.Context = aCtx
 	},

error_templates/java/arithmetic_exception.go

@@ -1,8 +1,6 @@
 package java
 
 import (
-	"strings"
-
 	lib "github.com/nedpals/errgoengine"
 )
 
@@ -38,15 +36,10 @@ var ArithmeticException = lib.ErrorTemplate{
 		}
 
 		if len(query) != 0 {
-			lib.QueryNode(cd.MainError.Nearest, strings.NewReader(query), func(ctx lib.QueryNodeCtx) bool {
-				match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(cd.MainError.Nearest.Doc.Contents))
-				for _, c := range match.Captures {
-					node := lib.WrapNode(cd.MainError.Nearest.Doc, c.Node)
-					err.Nearest = node
-					return false
-				}
-				return true
-			})
+			for q := err.Nearest.Query(query); q.Next(); {
+				err.Nearest = q.CurrentNode()
+				break
+			}
 		}
 
 		err.Context = ctx

error_templates/java/array_index_out_of_bounds_exception.go

@@ -3,7 +3,6 @@ package java
 import (
 	"fmt"
 	"strconv"
-	"strings"
 
 	lib "github.com/nedpals/errgoengine"
 )
@@ -12,15 +11,11 @@ var ArrayIndexOutOfBoundsException = lib.ErrorTemplate{
 	Name:    "ArrayIndexOutOfBoundsException",
 	Pattern: runtimeErrorPattern("java.lang.ArrayIndexOutOfBoundsException", `Index (?P<index>\d+) out of bounds for length (?P<length>\d+)`),
 	OnAnalyzeErrorFn: func(cd *lib.ContextData, m *lib.MainError) {
-		lib.QueryNode(m.Nearest, strings.NewReader("(array_access index: (_) @index)"), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				node := lib.WrapNode(m.Nearest.Doc, c.Node)
-				m.Nearest = node
-				return false
-			}
-			return true
-		})
+		for q := m.Nearest.Query(`(array_access index: (_) @index)`); q.Next(); {
+			node := q.CurrentNode()
+			m.Nearest = node
+			break
+		}
 	},
 	OnGenExplainFn: func(cd *lib.ContextData, gen *lib.ExplainGenerator) {
 		gen.Add("This error occurs because the code is trying to access index %s that is beyond the bounds of the array which only has %s items.", cd.Variables["index"], cd.Variables["length"])

error_templates/java/array_required_type_error.go

@@ -2,7 +2,6 @@ package java
 
 import (
 	"fmt"
-	"strings"
 
 	lib "github.com/nedpals/errgoengine"
 )
@@ -12,16 +11,10 @@ var ArrayRequiredTypeError = lib.ErrorTemplate{
 	Pattern:           comptimeErrorPattern(`array required, but (?P<foundType>\S+) found`),
 	StackTracePattern: comptimeStackTracePattern,
 	OnAnalyzeErrorFn: func(cd *lib.ContextData, err *lib.MainError) {
-		query := strings.NewReader("(array_access array: (identifier) index: ((_) @index (#eq? @index \"0\")))")
-		lib.QueryNode(cd.MainError.Nearest, query, func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(cd.MainError.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				node := lib.WrapNode(cd.MainError.Nearest.Doc, c.Node)
-				err.Nearest = node
-				return false
-			}
-			return true
-		})
+		for q := cd.MainError.Nearest.Query("(array_access array: (identifier) index: ((_) @index (#eq? @index \"0\")))"); q.Next(); {
+			err.Nearest = q.CurrentNode()
+			break
+		}
 	},
 	OnGenExplainFn: func(cd *lib.ContextData, gen *lib.ExplainGenerator) {
 		parent := cd.MainError.Nearest.Parent()

error_templates/java/bracket_mismatch_error.go

@@ -3,7 +3,6 @@ package java
 import (
 	"fmt"
 	"strconv"
-	"strings"
 
 	lib "github.com/nedpals/errgoengine"
 )
@@ -12,15 +11,11 @@ var BracketMismatchError = lib.ErrorTemplate{
 	Name:    "ArrayIndexOutOfBoundsException",
 	Pattern: comptimeErrorPattern(`'(?P<expected>\S+)' expected`),
 	OnAnalyzeErrorFn: func(cd *lib.ContextData, m *lib.MainError) {
-		lib.QueryNode(m.Nearest, strings.NewReader("(array_access index: (_) @index)"), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				node := lib.WrapNode(m.Nearest.Doc, c.Node)
-				m.Nearest = node
-				return false
-			}
-			return true
-		})
+		for q := m.Nearest.Query(`(array_access index: (_) @index)`); q.Next(); {
+			node := q.CurrentNode()
+			m.Nearest = node
+			break
+		}
 	},
 	OnGenExplainFn: func(cd *lib.ContextData, gen *lib.ExplainGenerator) {
 		gen.Add("This error occurs because the code is trying to access index %s that is beyond the bounds of the array which only has %s items.", cd.Variables["index"], cd.Variables["length"])

error_templates/java/cannot_be_applied_error.go

@@ -85,20 +85,15 @@ var CannotBeAppliedError = lib.ErrorTemplate{
 			argumentNodeTypesToLook += nTypesStr
 		}
 
-		rawQuery := fmt.Sprintf(`((method_invocation name: (identifier) @name arguments: (argument_list %s)) @call (#eq? @name "%s"))`, argumentNodeTypesToLook, cd.Variables["method"])
-
-		lib.QueryNode(m.Nearest, strings.NewReader(rawQuery), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				node := lib.WrapNode(m.Document, c.Node)
-				fmt.Println(node.Text())
-				cCtx.callExprNode = node
-				argNode := node.ChildByFieldName("arguments").NamedChild(cCtx.invalidIdx)
-				m.Nearest = argNode
-				return false
-			}
-			return true
-		})
+		for q := cd.MainError.Nearest.Query(
+			`((method_invocation name: (identifier) @name arguments: (argument_list %s)) @call (#eq? @name "%s"))`,
+			argumentNodeTypesToLook, cd.Variables["method"],
+		); q.Next(); {
+			node := q.CurrentNode()
+			cCtx.callExprNode = node
+			m.Nearest = node.ChildByFieldName("arguments").NamedChild(cCtx.invalidIdx)
+			break
+		}
 
 		m.Context = cCtx
 	},

error_templates/java/illegal_expression_start_error.go

@@ -1,8 +1,6 @@
 package java
 
 import (
-	"strings"
-
 	lib "github.com/nedpals/errgoengine"
 )
 
@@ -11,16 +9,12 @@ var IllegalExpressionStartError = lib.ErrorTemplate{
 	Pattern:           comptimeErrorPattern(`illegal start of expression`),
 	StackTracePattern: comptimeStackTracePattern,
 	OnAnalyzeErrorFn: func(cd *lib.ContextData, m *lib.MainError) {
-		lib.QueryNode(m.Nearest, strings.NewReader("(ERROR) @error"), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				node := lib.WrapNode(m.Nearest.Doc, c.Node)
-				m.Nearest = node
-				// aCtx.NearestClass = node
-				return false
-			}
-			return true
-		})
+		for q := m.Nearest.Query("(ERROR) @error"); q.Next(); {
+			node := q.CurrentNode()
+			m.Nearest = node
+			// aCtx.NearestClass = node
+			break
+		}
 	},
 	OnGenExplainFn: func(cd *lib.ContextData, gen *lib.ExplainGenerator) {
 		gen.Add("This error occurs when the compiler encounters an expression that is not valid.")

error_templates/java/invalid_method_declaration_error.go

@@ -2,7 +2,6 @@ package java
 
 import (
 	"fmt"
-	"strings"
 
 	lib "github.com/nedpals/errgoengine"
 )
@@ -20,20 +19,16 @@ var InvalidMethodDeclarationError = lib.ErrorTemplate{
 		iCtx := invalidMethodDeclarationErrorCtx{}
 		pos := m.ErrorNode.StartPos
 
-		lib.QueryNode(m.Document.RootNode(), strings.NewReader("(constructor_declaration) @method"), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				pointA := c.Node.StartPoint()
-				pointB := c.Node.EndPoint()
-				if uint32(pos.Line) >= pointA.Row+1 && uint32(pos.Line) <= pointB.Row+1 {
-					node := lib.WrapNode(m.Nearest.Doc, c.Node)
-					iCtx.declNode = node
-					m.Nearest = node.ChildByFieldName("name")
-					return false
-				}
+		for q := m.Document.RootNode().Query("(constructor_declaration) @method"); q.Next(); {
+			node := q.CurrentNode()
+			pointA := node.StartPoint()
+			pointB := node.EndPoint()
+			if uint32(pos.Line) >= pointA.Row+1 && uint32(pos.Line) <= pointB.Row+1 {
+				iCtx.declNode = node
+				m.Nearest = node.ChildByFieldName("name")
+				break
 			}
-			return true
-		})
+		}
 
 		iCtx.returnTypeToAdd = lib.UnwrapReturnType(cd.FindSymbol(m.Nearest.Text(), m.Nearest.StartPosition().Index))
 		m.Context = iCtx

error_templates/java/missing_return_error.go

@@ -3,7 +3,6 @@ package java
 import (
 	"context"
 	"fmt"
-	"strings"
 
 	lib "github.com/nedpals/errgoengine"
 )
@@ -21,19 +20,17 @@ var MissingReturnError = lib.ErrorTemplate{
 		mCtx := missingReturnErrorCtx{}
 		rootNode := m.Document.RootNode()
 		pos := m.ErrorNode.StartPos
-		lib.QueryNode(rootNode, strings.NewReader("(method_declaration) @method"), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				pointA := c.Node.StartPoint()
-				pointB := c.Node.EndPoint()
-				if uint32(pos.Line) >= pointA.Row+1 && uint32(pos.Line) <= pointB.Row+1 {
-					node := lib.WrapNode(m.Nearest.Doc, c.Node)
-					mCtx.NearestMethod = node
-					return false
-				}
+
+		for q := rootNode.Query("(method_declaration) @method"); q.Next(); {
+			node := q.CurrentNode()
+			pointA := node.StartPoint()
+			pointB := node.EndPoint()
+			if uint32(pos.Line) >= pointA.Row+1 && uint32(pos.Line) <= pointB.Row+1 {
+				mCtx.NearestMethod = node
+				break
 			}
-			return true
-		})
+		}
+
 		m.Context = mCtx
 	},
 	OnGenExplainFn: func(cd *lib.ContextData, gen *lib.ExplainGenerator) {

error_templates/java/negative_array_size_exception.go

@@ -1,8 +1,6 @@
 package java
 
 import (
-	"strings"
-
 	lib "github.com/nedpals/errgoengine"
 )
 
@@ -16,16 +14,13 @@ var NegativeArraySizeException = lib.ErrorTemplate{
 	OnAnalyzeErrorFn: func(cd *lib.ContextData, m *lib.MainError) {
 		nCtx := negativeArraySizeExceptionCtx{}
 		query := "(array_creation_expression dimensions: (dimensions_expr (unary_expression operand: (decimal_integer_literal)))) @array"
-		lib.QueryNode(m.Nearest, strings.NewReader(query), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				node := lib.WrapNode(m.Nearest.Doc, c.Node)
-				nCtx.ArrayExprNode = node
-				m.Nearest = node.ChildByFieldName("dimensions").NamedChild(0)
-				return false
-			}
-			return true
-		})
+		for q := m.Nearest.Query(query); q.Next(); {
+			node := q.CurrentNode()
+			nCtx.ArrayExprNode = node
+			m.Nearest = node.ChildByFieldName("dimensions").NamedChild(0)
+			break
+		}
+
 		m.Context = nCtx
 	},
 	OnGenExplainFn: func(cd *lib.ContextData, gen *lib.ExplainGenerator) {

error_templates/java/non_static_method_access_error.go

@@ -2,7 +2,6 @@ package java
 
 import (
 	"fmt"
-	"strings"
 
 	lib "github.com/nedpals/errgoengine"
 )
@@ -29,18 +28,14 @@ var NonStaticMethodAccessError = lib.ErrorTemplate{
 			}
 		}
 
-		m.Context = nCtx
+		for q := m.Nearest.Query(`(method_invocation name: (identifier) @method arguments: (argument_list))`); q.Next(); {
+			node := q.CurrentNode()
+			m.Nearest = node
+			nCtx.method = node.Text()
+			break
+		}
 
-		lib.QueryNode(m.Nearest, strings.NewReader("(method_invocation name: (identifier) @method arguments: (argument_list))"), func(ctx lib.QueryNodeCtx) bool {
-			match := ctx.Cursor.FilterPredicates(ctx.Match, []byte(m.Nearest.Doc.Contents))
-			for _, c := range match.Captures {
-				node := lib.WrapNode(m.Nearest.Doc, c.Node)
-				m.Nearest = node
-				nCtx.method = node.Text()
-				return false
-			}
-			return true
-		})
+		m.Context = nCtx
 	},
 	OnGenExplainFn: func(cd *lib.ContextData, gen *lib.ExplainGenerator) {
 		gen.Add("This error occurs when trying to access a non-static method from a static context. In Java, a non-static method belongs to an instance of the class and needs an object to be called upon.")

error_templates/java/null_pointer_exception.go

@@ -107,6 +107,12 @@ var NullPointerException = lib.ErrorTemplate{
 		gen.Add("Your program try to access or manipulate an object reference that is currently pointing to `null`, meaning it doesn't refer to any actual object in memory. This typically happens when you forget to initialize an object before using it, or when you try to access an object that hasn't been properly assigned a value. ")
 	},
 	OnGenBugFixFn: func(cd *lib.ContextData, gen *lib.BugFixGenerator) {
+		gen.Add("Wrap with an if statement", func(s *lib.BugFixSuggestion) {
+			s.AddDescription("Check for the variable that is being used as `null`.")
+		})
 
+		gen.Add("Initialize the variable", func(s *lib.BugFixSuggestion) {
+			s.AddDescription("An alternative fix is to initialize the `test` variable with a non-null value before calling the method.")
+		})
 	},
 }