# The CLI replaces one typed constant in a private function body, updates every direct caller, and refuses mutable reads and unknown nested fields without changing files.
cp service.go .scratch/service-before.txt
! exec semedit refactor-introduce-parameter --file service.go --symbol transform --parameters '[{"source_index":0,"parameter":{"name":"id","type":"int"}},{"parameter":{"name":"mode","type":"int"},"argument":"3"}]' --discriminator defaultMode --expected-revision stale
stderr 'expected_revision'
cmp service.go .scratch/service-before.txt
! exec semedit refactor-introduce-parameter --file service.go --symbol transform --parameters '[{"source_index":0,"parameter":{"name":"id","type":"int"}},{"parameter":{"name":"mode","type":"int"},"argument":"4"}]' --discriminator defaultMode
stderr 'selected expression'
cmp service.go .scratch/service-before.txt
! exec semedit refactor-introduce-parameter --file service.go --symbol shadowed --parameters '[{"source_index":0,"parameter":{"name":"id","type":"int"}},{"parameter":{"name":"mode","type":"int"},"argument":"3"}]' --discriminator defaultMode
stderr 'compile-time typed constant'
cmp service.go .scratch/service-before.txt
! exec semedit refactor-introduce-parameter --file service.go --symbol repeated --parameters '[{"source_index":0,"parameter":{"name":"flag","type":"bool"}},{"parameter":{"name":"enabled","type":"bool"},"argument":"true"}]' --discriminator true
stderr 'resolve uniquely'
cmp service.go .scratch/service-before.txt
! exec semedit refactor-introduce-parameter --file service.go --symbol constantDecl --parameters '[{"parameter":{"name":"enabled","type":"bool"},"argument":"true"}]' --discriminator true
stderr 'is not constant'
cmp service.go .scratch/service-before.txt
! exec semedit refactor-introduce-parameter --file service.go --symbol overflow --parameters '[{"parameter":{"name":"small","type":"int8"},"argument":"257"}]' --discriminator large
stderr 'assignable to the appended parameter type'
cmp service.go .scratch/service-before.txt
exec semedit refactor-introduce-parameter --file service.go --symbol transform --parameters '[{"source_index":0,"parameter":{"name":"id","type":"int"}},{"parameter":{"name":"mode","type":"mode"},"argument":"3"}]' --discriminator defaultMode
stdout 'Replaced the selected constant expression'
cmp service.go .scratch/want/service.txt
cmp calls.go .scratch/want/calls.txt
cmp other.go .scratch/want/other.txt
cmp service_test.go .scratch/want/service_test.txt
exec go test ./...
cp service.go .scratch/service.txt
! exec semedit refactor-introduce-parameter --file service.go --symbol unsafe --parameters '[{"source_index":0,"parameter":{"name":"id","type":"int"}},{"parameter":{"name":"mode","type":"int"},"argument":"2"}]' --discriminator mutableMode
stderr 'compile-time typed constant'
cmp service.go .scratch/service.txt
! exec semedit refactor-introduce-parameter --file service.go --symbol transform --parameters '[{"source_index":0,"parameter":{"name":"id","type":"int"}},{"parameter":{"name":"mode","type":"int"},"argument":"3","unknown":true}]' --discriminator defaultMode
stderr 'unknown property'
cmp service.go .scratch/service.txt
-- go.mod --
module example.com/introduceparameter

go 1.24
-- service.go --
package sample

type mode int

const defaultMode mode = 3
var mutableMode = 2

func transform(id int) int { return id + int(defaultMode) }
func unsafe(id int) int { return id + mutableMode }
func shadowed(id int) int { defaultMode := 4; return id + defaultMode }
func repeated(flag bool) bool { if flag { return true }; return true }
func constantDecl() bool { const value = true; return value }
const large = 257
func overflow() int { return int(large) }
-- service_test.go --
package sample

import "testing"

func TestTransform(t *testing.T) {
	if got := transform(5); got != 8 {
		t.Fatalf("transform(5) = %d, want 8", got)
	}
}
-- calls.go --
package sample

func first() int { return transform(1) }
func overflowCaller() int { return overflow() }
-- other.go --
package sample

func second() int { return transform(2) }
-- .scratch/want/service.txt --
package sample

type mode int

const defaultMode mode = 3
var mutableMode = 2

func transform(id int, mode mode) int { return id + int(mode) }
func unsafe(id int) int { return id + mutableMode }
func shadowed(id int) int { defaultMode := 4; return id + defaultMode }
func repeated(flag bool) bool { if flag { return true }; return true }
func constantDecl() bool { const value = true; return value }
const large = 257
func overflow() int { return int(large) }
-- .scratch/want/calls.txt --
package sample

func first() int { return transform(1, 3) }
func overflowCaller() int { return overflow() }
-- .scratch/want/other.txt --
package sample

func second() int { return transform(2, 3) }
-- .scratch/want/service_test.txt --
package sample

import "testing"

func TestTransform(t *testing.T) {
	if got := transform(5, 3); got != 8 {
		t.Fatalf("transform(5) = %d, want 8", got)
	}
}