chore: vendor

vendor/gotest.tools/v3/internal/source/source.go

@@ -0,0 +1,148 @@
+// Package source provides utilities for handling source-code.
+package source // import "gotest.tools/v3/internal/source"
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/parser"
+	"go/token"
+	"os"
+	"runtime"
+)
+
+// FormattedCallExprArg returns the argument from an ast.CallExpr at the
+// index in the call stack. The argument is formatted using FormatNode.
+func FormattedCallExprArg(stackIndex int, argPos int) (string, error) {
+	args, err := CallExprArgs(stackIndex + 1)
+	if err != nil {
+		return "", err
+	}
+	if argPos >= len(args) {
+		return "", errors.New("failed to find expression")
+	}
+	return FormatNode(args[argPos])
+}
+
+// CallExprArgs returns the ast.Expr slice for the args of an ast.CallExpr at
+// the index in the call stack.
+func CallExprArgs(stackIndex int) ([]ast.Expr, error) {
+	_, filename, line, ok := runtime.Caller(stackIndex + 1)
+	if !ok {
+		return nil, errors.New("failed to get call stack")
+	}
+	debug("call stack position: %s:%d", filename, line)
+
+	fileset := token.NewFileSet()
+	astFile, err := parser.ParseFile(fileset, filename, nil, parser.AllErrors)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse source file %s: %w", filename, err)
+	}
+
+	expr, err := getCallExprArgs(fileset, astFile, line)
+	if err != nil {
+		return nil, fmt.Errorf("call from %s:%d: %w", filename, line, err)
+	}
+	return expr, nil
+}
+
+func getNodeAtLine(fileset *token.FileSet, astFile ast.Node, lineNum int) (ast.Node, error) {
+	if node := scanToLine(fileset, astFile, lineNum); node != nil {
+		return node, nil
+	}
+	if node := scanToDeferLine(fileset, astFile, lineNum); node != nil {
+		node, err := guessDefer(node)
+		if err != nil || node != nil {
+			return node, err
+		}
+	}
+	return nil, nil
+}
+
+func scanToLine(fileset *token.FileSet, node ast.Node, lineNum int) ast.Node {
+	var matchedNode ast.Node
+	ast.Inspect(node, func(node ast.Node) bool {
+		switch {
+		case node == nil || matchedNode != nil:
+			return false
+		case fileset.Position(node.Pos()).Line == lineNum:
+			matchedNode = node
+			return false
+		}
+		return true
+	})
+	return matchedNode
+}
+
+func getCallExprArgs(fileset *token.FileSet, astFile ast.Node, line int) ([]ast.Expr, error) {
+	node, err := getNodeAtLine(fileset, astFile, line)
+	switch {
+	case err != nil:
+		return nil, err
+	case node == nil:
+		return nil, fmt.Errorf("failed to find an expression")
+	}
+
+	debug("found node: %s", debugFormatNode{node})
+
+	visitor := &callExprVisitor{}
+	ast.Walk(visitor, node)
+	if visitor.expr == nil {
+		return nil, errors.New("failed to find call expression")
+	}
+	debug("callExpr: %s", debugFormatNode{visitor.expr})
+	return visitor.expr.Args, nil
+}
+
+type callExprVisitor struct {
+	expr *ast.CallExpr
+}
+
+func (v *callExprVisitor) Visit(node ast.Node) ast.Visitor {
+	if v.expr != nil || node == nil {
+		return nil
+	}
+	debug("visit: %s", debugFormatNode{node})
+
+	switch typed := node.(type) {
+	case *ast.CallExpr:
+		v.expr = typed
+		return nil
+	case *ast.DeferStmt:
+		ast.Walk(v, typed.Call.Fun)
+		return nil
+	}
+	return v
+}
+
+// FormatNode using go/format.Node and return the result as a string
+func FormatNode(node ast.Node) (string, error) {
+	buf := new(bytes.Buffer)
+	err := format.Node(buf, token.NewFileSet(), node)
+	return buf.String(), err
+}
+
+var debugEnabled = os.Getenv("GOTESTTOOLS_DEBUG") != ""
+
+func debug(format string, args ...interface{}) {
+	if debugEnabled {
+		fmt.Fprintf(os.Stderr, "DEBUG: "+format+"\n", args...)
+	}
+}
+
+type debugFormatNode struct {
+	ast.Node
+}
+
+func (n debugFormatNode) String() string {
+	if n.Node == nil {
+		return "none"
+	}
+	out, err := FormatNode(n.Node)
+	if err != nil {
+		return fmt.Sprintf("failed to format %s: %s", n.Node, err)
+	}
+	return fmt.Sprintf("(%T) %s", n.Node, out)
+}