

-- go.mod --
module example.com
go 1.18

-- template/template.go --
package template

// Basic test of type-aware expression refactoring.

import (
	"errors"
	"fmt"
)

func before(s string) error { return fmt.Errorf("%s", s) }
func after(s string) error  { return errors.New(s) }

-- in/a1/a1.go --
package a1

import (
	. "fmt"
	myfmt "fmt"
	"os"
	"strings"
)

func example(n int) {
	x := "foo" + strings.Repeat("\t", n)
	// Match, despite named import.
	myfmt.Errorf("%s", x)

	// Match, despite dot import.
	Errorf("%s", x)

	// Match: multiple matches in same function are possible.
	myfmt.Errorf("%s", x)

	// No match: wildcarded operand has the wrong type.
	myfmt.Errorf("%s", 3)

	// No match: function operand doesn't match.
	myfmt.Printf("%s", x)

	// No match again, dot import.
	Printf("%s", x)

	// Match.
	myfmt.Fprint(os.Stderr, myfmt.Errorf("%s", x+"foo"))

	// No match: though this literally matches the template,
	// fmt doesn't resolve to a package here.
	var fmt struct{ Errorf func(string, string) }
	fmt.Errorf("%s", x)

	// Recursive matching:

	// Match: both matches are well-typed, so both succeed.
	myfmt.Errorf("%s", myfmt.Errorf("%s", x+"foo").Error())

	// Outer match succeeds, inner doesn't: 3 has wrong type.
	myfmt.Errorf("%s", myfmt.Errorf("%s", 3).Error())

	// Inner match succeeds, outer doesn't: the inner replacement
	// has the wrong type (error not string).
	myfmt.Errorf("%s", myfmt.Errorf("%s", x+"foo"))
}

-- out/a1/a1.go --
package a1

import (
	"errors"
	. "fmt"
	myfmt "fmt"
	"os"
	"strings"
)

func example(n int) {
	x := "foo" + strings.Repeat("\t", n)
	// Match, despite named import.
	errors.New(x)

	// Match, despite dot import.
	errors.New(x)

	// Match: multiple matches in same function are possible.
	errors.New(x)

	// No match: wildcarded operand has the wrong type.
	myfmt.Errorf("%s", 3)

	// No match: function operand doesn't match.
	myfmt.Printf("%s", x)

	// No match again, dot import.
	Printf("%s", x)

	// Match.
	myfmt.Fprint(os.Stderr, errors.New(x+"foo"))

	// No match: though this literally matches the template,
	// fmt doesn't resolve to a package here.
	var fmt struct{ Errorf func(string, string) }
	fmt.Errorf("%s", x)

	// Recursive matching:

	// Match: both matches are well-typed, so both succeed.
	errors.New(errors.New(x + "foo").Error())

	// Outer match succeeds, inner doesn't: 3 has wrong type.
	errors.New(myfmt.Errorf("%s", 3).Error())

	// Inner match succeeds, outer doesn't: the inner replacement
	// has the wrong type (error not string).
	myfmt.Errorf("%s", errors.New(x+"foo"))
}
-- a2/a2.go --
package a2

// This refactoring causes addition of "errors" import.
// TODO(adonovan): fix: it should also remove "fmt".

import myfmt "fmt"

func example(n int) {
	myfmt.Errorf("%s", "")
}

-- out/a2/a2.go --
package a2

// This refactoring causes addition of "errors" import.
// TODO(adonovan): fix: it should also remove "fmt".

import (
	"errors"
	myfmt "fmt"
)

func example(n int) {
	errors.New("")
}