vendor/github.com/golang/mock/gomock/call.go - voltha-go - Gitiles

 // Copyright 2010 Google Inc.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package gomock

 import (
 	"fmt"
 	"reflect"
 	"strconv"
 	"strings"
 )

 // Call represents an expected call to a mock.
 type Call struct {
 	t TestHelper // for triggering test failures on invalid call setup

 	receiver   interface{}  // the receiver of the method call
 	method     string       // the name of the method
 	methodType reflect.Type // the type of the method
 	args       []Matcher    // the args
 	origin     string       // file and line number of call setup

 	preReqs []*Call // prerequisite calls

 	// Expectations
 	minCalls, maxCalls int

 	numCalls int // actual number made

 	// actions are called when this Call is called. Each action gets the args and
 	// can set the return values by returning a non-nil slice. Actions run in the
 	// order they are created.
 	actions []func([]interface{}) []interface{}
 }

 // newCall creates a *Call. It requires the method type in order to support
 // unexported methods.
 func newCall(t TestHelper, receiver interface{}, method string, methodType reflect.Type, args ...interface{}) *Call {
 	t.Helper()

 	// TODO: check arity, types.
 	mArgs := make([]Matcher, len(args))
 	for i, arg := range args {
 		if m, ok := arg.(Matcher); ok {
 			mArgs[i] = m
 		} else if arg == nil {
 			// Handle nil specially so that passing a nil interface value
 			// will match the typed nils of concrete args.
 			mArgs[i] = Nil()
 		} else {
 			mArgs[i] = Eq(arg)
 		}
 	}

 	// callerInfo's skip should be updated if the number of calls between the user's test
 	// and this line changes, i.e. this code is wrapped in another anonymous function.
 	// 0 is us, 1 is RecordCallWithMethodType(), 2 is the generated recorder, and 3 is the user's test.
 	origin := callerInfo(3)
 	actions := []func([]interface{}) []interface{}{func([]interface{}) []interface{} {
 		// Synthesize the zero value for each of the return args' types.
 		rets := make([]interface{}, methodType.NumOut())
 		for i := 0; i < methodType.NumOut(); i++ {
 			rets[i] = reflect.Zero(methodType.Out(i)).Interface()
 		}
 		return rets
 	}}
 	return &Call{t: t, receiver: receiver, method: method, methodType: methodType,
 		args: mArgs, origin: origin, minCalls: 1, maxCalls: 1, actions: actions}
 }

 // AnyTimes allows the expectation to be called 0 or more times
 func (c *Call) AnyTimes() *Call {
 	c.minCalls, c.maxCalls = 0, 1e8 // close enough to infinity
 	return c
 }

 // MinTimes requires the call to occur at least n times. If AnyTimes or MaxTimes have not been called or if MaxTimes
 // was previously called with 1, MinTimes also sets the maximum number of calls to infinity.
 func (c *Call) MinTimes(n int) *Call {
 	c.minCalls = n
 	if c.maxCalls == 1 {
 		c.maxCalls = 1e8
 	}
 	return c
 }

 // MaxTimes limits the number of calls to n times. If AnyTimes or MinTimes have not been called or if MinTimes was
 // previously called with 1, MaxTimes also sets the minimum number of calls to 0.
 func (c *Call) MaxTimes(n int) *Call {
 	c.maxCalls = n
 	if c.minCalls == 1 {
 		c.minCalls = 0
 	}
 	return c
 }

 // DoAndReturn declares the action to run when the call is matched.
 // The return values from this function are returned by the mocked function.
 // It takes an interface{} argument to support n-arity functions.
 func (c *Call) DoAndReturn(f interface{}) *Call {
 	// TODO: Check arity and types here, rather than dying badly elsewhere.
 	v := reflect.ValueOf(f)

 	c.addAction(func(args []interface{}) []interface{} {
 		c.t.Helper()
 		vArgs := make([]reflect.Value, len(args))
 		ft := v.Type()
 		if c.methodType.NumIn() != ft.NumIn() {
 			c.t.Fatalf("wrong number of arguments in DoAndReturn func for %T.%v: got %d, want %d [%s]",
 				c.receiver, c.method, ft.NumIn(), c.methodType.NumIn(), c.origin)
 			return nil
 		}
 		for i := 0; i < len(args); i++ {
 			if args[i] != nil {
 				vArgs[i] = reflect.ValueOf(args[i])
 			} else {
 				// Use the zero value for the arg.
 				vArgs[i] = reflect.Zero(ft.In(i))
 			}
 		}
 		vRets := v.Call(vArgs)
 		rets := make([]interface{}, len(vRets))
 		for i, ret := range vRets {
 			rets[i] = ret.Interface()
 		}
 		return rets
 	})
 	return c
 }

 // Do declares the action to run when the call is matched. The function's
 // return values are ignored to retain backward compatibility. To use the
 // return values call DoAndReturn.
 // It takes an interface{} argument to support n-arity functions.
 func (c *Call) Do(f interface{}) *Call {
 	// TODO: Check arity and types here, rather than dying badly elsewhere.
 	v := reflect.ValueOf(f)

 	c.addAction(func(args []interface{}) []interface{} {
 		c.t.Helper()
 		if c.methodType.NumIn() != v.Type().NumIn() {
 			c.t.Fatalf("wrong number of arguments in Do func for %T.%v: got %d, want %d [%s]",
 				c.receiver, c.method, v.Type().NumIn(), c.methodType.NumIn(), c.origin)
 			return nil
 		}
 		vArgs := make([]reflect.Value, len(args))
 		ft := v.Type()
 		for i := 0; i < len(args); i++ {
 			if args[i] != nil {
 				vArgs[i] = reflect.ValueOf(args[i])
 			} else {
 				// Use the zero value for the arg.
 				vArgs[i] = reflect.Zero(ft.In(i))
 			}
 		}
 		v.Call(vArgs)
 		return nil
 	})
 	return c
 }

 // Return declares the values to be returned by the mocked function call.
 func (c *Call) Return(rets ...interface{}) *Call {
 	c.t.Helper()

 	mt := c.methodType
 	if len(rets) != mt.NumOut() {
 		c.t.Fatalf("wrong number of arguments to Return for %T.%v: got %d, want %d [%s]",
 			c.receiver, c.method, len(rets), mt.NumOut(), c.origin)
 	}
 	for i, ret := range rets {
 		if got, want := reflect.TypeOf(ret), mt.Out(i); got == want {
 			// Identical types; nothing to do.
 		} else if got == nil {
 			// Nil needs special handling.
 			switch want.Kind() {
 			case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
 				// ok
 			default:
 				c.t.Fatalf("argument %d to Return for %T.%v is nil, but %v is not nillable [%s]",
 					i, c.receiver, c.method, want, c.origin)
 			}
 		} else if got.AssignableTo(want) {
 			// Assignable type relation. Make the assignment now so that the generated code
 			// can return the values with a type assertion.
 			v := reflect.New(want).Elem()
 			v.Set(reflect.ValueOf(ret))
 			rets[i] = v.Interface()
 		} else {
 			c.t.Fatalf("wrong type of argument %d to Return for %T.%v: %v is not assignable to %v [%s]",
 				i, c.receiver, c.method, got, want, c.origin)
 		}
 	}

 	c.addAction(func([]interface{}) []interface{} {
 		return rets
 	})

 	return c
 }

 // Times declares the exact number of times a function call is expected to be executed.
 func (c *Call) Times(n int) *Call {
 	c.minCalls, c.maxCalls = n, n
 	return c
 }

 // SetArg declares an action that will set the nth argument's value,
 // indirected through a pointer. Or, in the case of a slice, SetArg
 // will copy value's elements into the nth argument.
 func (c *Call) SetArg(n int, value interface{}) *Call {
 	c.t.Helper()

 	mt := c.methodType
 	// TODO: This will break on variadic methods.
 	// We will need to check those at invocation time.
 	if n < 0 || n >= mt.NumIn() {
 		c.t.Fatalf("SetArg(%d, ...) called for a method with %d args [%s]",
 			n, mt.NumIn(), c.origin)
 	}
 	// Permit setting argument through an interface.
 	// In the interface case, we don't (nay, can't) check the type here.
 	at := mt.In(n)
 	switch at.Kind() {
 	case reflect.Ptr:
 		dt := at.Elem()
 		if vt := reflect.TypeOf(value); !vt.AssignableTo(dt) {
 			c.t.Fatalf("SetArg(%d, ...) argument is a %v, not assignable to %v [%s]",
 				n, vt, dt, c.origin)
 		}
 	case reflect.Interface:
 		// nothing to do
 	case reflect.Slice:
 		// nothing to do
 	default:
 		c.t.Fatalf("SetArg(%d, ...) referring to argument of non-pointer non-interface non-slice type %v [%s]",
 			n, at, c.origin)
 	}

 	c.addAction(func(args []interface{}) []interface{} {
 		v := reflect.ValueOf(value)
 		switch reflect.TypeOf(args[n]).Kind() {
 		case reflect.Slice:
 			setSlice(args[n], v)
 		default:
 			reflect.ValueOf(args[n]).Elem().Set(v)
 		}
 		return nil
 	})
 	return c
 }

 // isPreReq returns true if other is a direct or indirect prerequisite to c.
 func (c *Call) isPreReq(other *Call) bool {
 	for _, preReq := range c.preReqs {
 		if other == preReq || preReq.isPreReq(other) {
 			return true
 		}
 	}
 	return false
 }

 // After declares that the call may only match after preReq has been exhausted.
 func (c *Call) After(preReq *Call) *Call {
 	c.t.Helper()

 	if c == preReq {
 		c.t.Fatalf("A call isn't allowed to be its own prerequisite")
 	}
 	if preReq.isPreReq(c) {
 		c.t.Fatalf("Loop in call order: %v is a prerequisite to %v (possibly indirectly).", c, preReq)
 	}

 	c.preReqs = append(c.preReqs, preReq)
 	return c
 }

 // Returns true if the minimum number of calls have been made.
 func (c *Call) satisfied() bool {
 	return c.numCalls >= c.minCalls
 }

 // Returns true if the maximum number of calls have been made.
 func (c *Call) exhausted() bool {
 	return c.numCalls >= c.maxCalls
 }

 func (c *Call) String() string {
 	args := make([]string, len(c.args))
 	for i, arg := range c.args {
 		args[i] = arg.String()
 	}
 	arguments := strings.Join(args, ", ")
 	return fmt.Sprintf("%T.%v(%s) %s", c.receiver, c.method, arguments, c.origin)
 }

 // Tests if the given call matches the expected call.
 // If yes, returns nil. If no, returns error with message explaining why it does not match.
 func (c *Call) matches(args []interface{}) error {
 	if !c.methodType.IsVariadic() {
 		if len(args) != len(c.args) {
 			return fmt.Errorf("expected call at %s has the wrong number of arguments. Got: %d, want: %d",
 				c.origin, len(args), len(c.args))
 		}

 		for i, m := range c.args {
 			if !m.Matches(args[i]) {
 				return fmt.Errorf(
 					"expected call at %s doesn't match the argument at index %d.\nGot: %v\nWant: %v",
 					c.origin, i, formatGottenArg(m, args[i]), m,
 				)
 			}
 		}
 	} else {
 		if len(c.args) < c.methodType.NumIn()-1 {
 			return fmt.Errorf("expected call at %s has the wrong number of matchers. Got: %d, want: %d",
 				c.origin, len(c.args), c.methodType.NumIn()-1)
 		}
 		if len(c.args) != c.methodType.NumIn() && len(args) != len(c.args) {
 			return fmt.Errorf("expected call at %s has the wrong number of arguments. Got: %d, want: %d",
 				c.origin, len(args), len(c.args))
 		}
 		if len(args) < len(c.args)-1 {
 			return fmt.Errorf("expected call at %s has the wrong number of arguments. Got: %d, want: greater than or equal to %d",
 				c.origin, len(args), len(c.args)-1)
 		}

 		for i, m := range c.args {
 			if i < c.methodType.NumIn()-1 {
 				// Non-variadic args
 				if !m.Matches(args[i]) {
 					return fmt.Errorf("expected call at %s doesn't match the argument at index %s.\nGot: %v\nWant: %v",
 						c.origin, strconv.Itoa(i), formatGottenArg(m, args[i]), m)
 				}
 				continue
 			}
 			// The last arg has a possibility of a variadic argument, so let it branch

 			// sample: Foo(a int, b int, c ...int)
 			if i < len(c.args) && i < len(args) {
 				if m.Matches(args[i]) {
 					// Got Foo(a, b, c) want Foo(matcherA, matcherB, gomock.Any())
 					// Got Foo(a, b, c) want Foo(matcherA, matcherB, someSliceMatcher)
 					// Got Foo(a, b, c) want Foo(matcherA, matcherB, matcherC)
 					// Got Foo(a, b) want Foo(matcherA, matcherB)
 					// Got Foo(a, b, c, d) want Foo(matcherA, matcherB, matcherC, matcherD)
 					continue
 				}
 			}

 			// The number of actual args don't match the number of matchers,
 			// or the last matcher is a slice and the last arg is not.
 			// If this function still matches it is because the last matcher
 			// matches all the remaining arguments or the lack of any.
 			// Convert the remaining arguments, if any, into a slice of the
 			// expected type.
 			vArgsType := c.methodType.In(c.methodType.NumIn() - 1)
 			vArgs := reflect.MakeSlice(vArgsType, 0, len(args)-i)
 			for _, arg := range args[i:] {
 				vArgs = reflect.Append(vArgs, reflect.ValueOf(arg))
 			}
 			if m.Matches(vArgs.Interface()) {
 				// Got Foo(a, b, c, d, e) want Foo(matcherA, matcherB, gomock.Any())
 				// Got Foo(a, b, c, d, e) want Foo(matcherA, matcherB, someSliceMatcher)
 				// Got Foo(a, b) want Foo(matcherA, matcherB, gomock.Any())
 				// Got Foo(a, b) want Foo(matcherA, matcherB, someEmptySliceMatcher)
 				break
 			}
 			// Wrong number of matchers or not match. Fail.
 			// Got Foo(a, b) want Foo(matcherA, matcherB, matcherC, matcherD)
 			// Got Foo(a, b, c) want Foo(matcherA, matcherB, matcherC, matcherD)
 			// Got Foo(a, b, c, d) want Foo(matcherA, matcherB, matcherC, matcherD, matcherE)
 			// Got Foo(a, b, c, d, e) want Foo(matcherA, matcherB, matcherC, matcherD)
 			// Got Foo(a, b, c) want Foo(matcherA, matcherB)

 			return fmt.Errorf("expected call at %s doesn't match the argument at index %s.\nGot: %v\nWant: %v",
 				c.origin, strconv.Itoa(i), formatGottenArg(m, args[i:]), c.args[i])
 		}
 	}

 	// Check that all prerequisite calls have been satisfied.
 	for _, preReqCall := range c.preReqs {
 		if !preReqCall.satisfied() {
 			return fmt.Errorf("expected call at %s doesn't have a prerequisite call satisfied:\n%v\nshould be called before:\n%v",
 				c.origin, preReqCall, c)
 		}
 	}

 	// Check that the call is not exhausted.
 	if c.exhausted() {
 		return fmt.Errorf("expected call at %s has already been called the max number of times", c.origin)
 	}

 	return nil
 }

 // dropPrereqs tells the expected Call to not re-check prerequisite calls any
 // longer, and to return its current set.
 func (c *Call) dropPrereqs() (preReqs []*Call) {
 	preReqs = c.preReqs
 	c.preReqs = nil
 	return
 }

 func (c *Call) call() []func([]interface{}) []interface{} {
 	c.numCalls++
 	return c.actions
 }

 // InOrder declares that the given calls should occur in order.
 func InOrder(calls ...*Call) {
 	for i := 1; i < len(calls); i++ {
 		calls[i].After(calls[i-1])
 	}
 }

 func setSlice(arg interface{}, v reflect.Value) {
 	va := reflect.ValueOf(arg)
 	for i := 0; i < v.Len(); i++ {
 		va.Index(i).Set(v.Index(i))
 	}
 }

 func (c *Call) addAction(action func([]interface{}) []interface{}) {
 	c.actions = append(c.actions, action)
 }

 func formatGottenArg(m Matcher, arg interface{}) string {
 	got := fmt.Sprintf("%v (%T)", arg, arg)
 	if gs, ok := m.(GotFormatter); ok {
 		got = gs.Got(arg)
 	}
 	return got
 }
	// Copyright 2010 Google Inc.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package gomock

	import (
	"fmt"
	"reflect"
	"strconv"
	"strings"
	)

	// Call represents an expected call to a mock.
	type Call struct {
	t TestHelper // for triggering test failures on invalid call setup

	receiver interface{} // the receiver of the method call
	method string // the name of the method
	methodType reflect.Type // the type of the method
	args []Matcher // the args
	origin string // file and line number of call setup

	preReqs []*Call // prerequisite calls

	// Expectations
	minCalls, maxCalls int

	numCalls int // actual number made

	// actions are called when this Call is called. Each action gets the args and
	// can set the return values by returning a non-nil slice. Actions run in the
	// order they are created.
	actions []func([]interface{}) []interface{}
	}

	// newCall creates a *Call. It requires the method type in order to support
	// unexported methods.
	func newCall(t TestHelper, receiver interface{}, method string, methodType reflect.Type, args ...interface{}) *Call {
	t.Helper()

	// TODO: check arity, types.
	mArgs := make([]Matcher, len(args))
	for i, arg := range args {
	if m, ok := arg.(Matcher); ok {
	mArgs[i] = m
	} else if arg == nil {
	// Handle nil specially so that passing a nil interface value
	// will match the typed nils of concrete args.
	mArgs[i] = Nil()
	} else {
	mArgs[i] = Eq(arg)
	}
	}

	// callerInfo's skip should be updated if the number of calls between the user's test
	// and this line changes, i.e. this code is wrapped in another anonymous function.
	// 0 is us, 1 is RecordCallWithMethodType(), 2 is the generated recorder, and 3 is the user's test.
	origin := callerInfo(3)
	actions := []func([]interface{}) []interface{}{func([]interface{}) []interface{} {
	// Synthesize the zero value for each of the return args' types.
	rets := make([]interface{}, methodType.NumOut())
	for i := 0; i < methodType.NumOut(); i++ {
	rets[i] = reflect.Zero(methodType.Out(i)).Interface()
	}
	return rets
	}}
	return &Call{t: t, receiver: receiver, method: method, methodType: methodType,
	args: mArgs, origin: origin, minCalls: 1, maxCalls: 1, actions: actions}
	}

	// AnyTimes allows the expectation to be called 0 or more times
	func (c Call) AnyTimes() Call {
	c.minCalls, c.maxCalls = 0, 1e8 // close enough to infinity
	return c
	}

	// MinTimes requires the call to occur at least n times. If AnyTimes or MaxTimes have not been called or if MaxTimes
	// was previously called with 1, MinTimes also sets the maximum number of calls to infinity.
	func (c Call) MinTimes(n int) Call {
	c.minCalls = n
	if c.maxCalls == 1 {
	c.maxCalls = 1e8
	}
	return c
	}

	// MaxTimes limits the number of calls to n times. If AnyTimes or MinTimes have not been called or if MinTimes was
	// previously called with 1, MaxTimes also sets the minimum number of calls to 0.
	func (c Call) MaxTimes(n int) Call {
	c.maxCalls = n
	if c.minCalls == 1 {
	c.minCalls = 0
	}
	return c
	}

	// DoAndReturn declares the action to run when the call is matched.
	// The return values from this function are returned by the mocked function.
	// It takes an interface{} argument to support n-arity functions.
	func (c Call) DoAndReturn(f interface{}) Call {
	// TODO: Check arity and types here, rather than dying badly elsewhere.
	v := reflect.ValueOf(f)

	c.addAction(func(args []interface{}) []interface{} {
	c.t.Helper()
	vArgs := make([]reflect.Value, len(args))
	ft := v.Type()
	if c.methodType.NumIn() != ft.NumIn() {
	c.t.Fatalf("wrong number of arguments in DoAndReturn func for %T.%v: got %d, want %d [%s]",
	c.receiver, c.method, ft.NumIn(), c.methodType.NumIn(), c.origin)
	return nil
	}
	for i := 0; i < len(args); i++ {
	if args[i] != nil {
	vArgs[i] = reflect.ValueOf(args[i])
	} else {
	// Use the zero value for the arg.
	vArgs[i] = reflect.Zero(ft.In(i))
	}
	}
	vRets := v.Call(vArgs)
	rets := make([]interface{}, len(vRets))
	for i, ret := range vRets {
	rets[i] = ret.Interface()
	}
	return rets
	})
	return c
	}

	// Do declares the action to run when the call is matched. The function's
	// return values are ignored to retain backward compatibility. To use the
	// return values call DoAndReturn.
	// It takes an interface{} argument to support n-arity functions.
	func (c Call) Do(f interface{}) Call {
	// TODO: Check arity and types here, rather than dying badly elsewhere.
	v := reflect.ValueOf(f)

	c.addAction(func(args []interface{}) []interface{} {
	c.t.Helper()
	if c.methodType.NumIn() != v.Type().NumIn() {
	c.t.Fatalf("wrong number of arguments in Do func for %T.%v: got %d, want %d [%s]",
	c.receiver, c.method, v.Type().NumIn(), c.methodType.NumIn(), c.origin)
	return nil
	}
	vArgs := make([]reflect.Value, len(args))
	ft := v.Type()
	for i := 0; i < len(args); i++ {
	if args[i] != nil {
	vArgs[i] = reflect.ValueOf(args[i])
	} else {
	// Use the zero value for the arg.
	vArgs[i] = reflect.Zero(ft.In(i))
	}
	}
	v.Call(vArgs)
	return nil
	})
	return c
	}

	// Return declares the values to be returned by the mocked function call.
	func (c Call) Return(rets ...interface{}) Call {
	c.t.Helper()

	mt := c.methodType
	if len(rets) != mt.NumOut() {
	c.t.Fatalf("wrong number of arguments to Return for %T.%v: got %d, want %d [%s]",
	c.receiver, c.method, len(rets), mt.NumOut(), c.origin)
	}
	for i, ret := range rets {
	if got, want := reflect.TypeOf(ret), mt.Out(i); got == want {
	// Identical types; nothing to do.
	} else if got == nil {
	// Nil needs special handling.
	switch want.Kind() {
	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
	// ok
	default:
	c.t.Fatalf("argument %d to Return for %T.%v is nil, but %v is not nillable [%s]",
	i, c.receiver, c.method, want, c.origin)
	}
	} else if got.AssignableTo(want) {
	// Assignable type relation. Make the assignment now so that the generated code
	// can return the values with a type assertion.
	v := reflect.New(want).Elem()
	v.Set(reflect.ValueOf(ret))
	rets[i] = v.Interface()
	} else {
	c.t.Fatalf("wrong type of argument %d to Return for %T.%v: %v is not assignable to %v [%s]",
	i, c.receiver, c.method, got, want, c.origin)
	}
	}

	c.addAction(func([]interface{}) []interface{} {
	return rets
	})

	return c
	}

	// Times declares the exact number of times a function call is expected to be executed.
	func (c Call) Times(n int) Call {
	c.minCalls, c.maxCalls = n, n
	return c
	}

	// SetArg declares an action that will set the nth argument's value,
	// indirected through a pointer. Or, in the case of a slice, SetArg
	// will copy value's elements into the nth argument.
	func (c Call) SetArg(n int, value interface{}) Call {
	c.t.Helper()

	mt := c.methodType
	// TODO: This will break on variadic methods.
	// We will need to check those at invocation time.
	if n < 0 \|\| n >= mt.NumIn() {
	c.t.Fatalf("SetArg(%d, ...) called for a method with %d args [%s]",
	n, mt.NumIn(), c.origin)
	}
	// Permit setting argument through an interface.
	// In the interface case, we don't (nay, can't) check the type here.
	at := mt.In(n)
	switch at.Kind() {
	case reflect.Ptr:
	dt := at.Elem()
	if vt := reflect.TypeOf(value); !vt.AssignableTo(dt) {
	c.t.Fatalf("SetArg(%d, ...) argument is a %v, not assignable to %v [%s]",
	n, vt, dt, c.origin)
	}
	case reflect.Interface:
	// nothing to do
	case reflect.Slice:
	// nothing to do
	default:
	c.t.Fatalf("SetArg(%d, ...) referring to argument of non-pointer non-interface non-slice type %v [%s]",
	n, at, c.origin)
	}

	c.addAction(func(args []interface{}) []interface{} {
	v := reflect.ValueOf(value)
	switch reflect.TypeOf(args[n]).Kind() {
	case reflect.Slice:
	setSlice(args[n], v)
	default:
	reflect.ValueOf(args[n]).Elem().Set(v)
	}
	return nil
	})
	return c
	}

	// isPreReq returns true if other is a direct or indirect prerequisite to c.
	func (c Call) isPreReq(other Call) bool {
	for _, preReq := range c.preReqs {
	if other == preReq \|\| preReq.isPreReq(other) {
	return true
	}
	}
	return false
	}

	// After declares that the call may only match after preReq has been exhausted.
	func (c Call) After(preReq Call) *Call {
	c.t.Helper()

	if c == preReq {
	c.t.Fatalf("A call isn't allowed to be its own prerequisite")
	}
	if preReq.isPreReq(c) {
	c.t.Fatalf("Loop in call order: %v is a prerequisite to %v (possibly indirectly).", c, preReq)
	}

	c.preReqs = append(c.preReqs, preReq)
	return c
	}

	// Returns true if the minimum number of calls have been made.
	func (c *Call) satisfied() bool {
	return c.numCalls >= c.minCalls
	}

	// Returns true if the maximum number of calls have been made.
	func (c *Call) exhausted() bool {
	return c.numCalls >= c.maxCalls
	}

	func (c *Call) String() string {
	args := make([]string, len(c.args))
	for i, arg := range c.args {
	args[i] = arg.String()
	}
	arguments := strings.Join(args, ", ")
	return fmt.Sprintf("%T.%v(%s) %s", c.receiver, c.method, arguments, c.origin)
	}

	// Tests if the given call matches the expected call.
	// If yes, returns nil. If no, returns error with message explaining why it does not match.
	func (c *Call) matches(args []interface{}) error {
	if !c.methodType.IsVariadic() {
	if len(args) != len(c.args) {
	return fmt.Errorf("expected call at %s has the wrong number of arguments. Got: %d, want: %d",
	c.origin, len(args), len(c.args))
	}

	for i, m := range c.args {
	if !m.Matches(args[i]) {
	return fmt.Errorf(
	"expected call at %s doesn't match the argument at index %d.\nGot: %v\nWant: %v",
	c.origin, i, formatGottenArg(m, args[i]), m,
	)
	}
	}
	} else {
	if len(c.args) < c.methodType.NumIn()-1 {
	return fmt.Errorf("expected call at %s has the wrong number of matchers. Got: %d, want: %d",
	c.origin, len(c.args), c.methodType.NumIn()-1)
	}
	if len(c.args) != c.methodType.NumIn() && len(args) != len(c.args) {
	return fmt.Errorf("expected call at %s has the wrong number of arguments. Got: %d, want: %d",
	c.origin, len(args), len(c.args))
	}
	if len(args) < len(c.args)-1 {
	return fmt.Errorf("expected call at %s has the wrong number of arguments. Got: %d, want: greater than or equal to %d",
	c.origin, len(args), len(c.args)-1)
	}

	for i, m := range c.args {
	if i < c.methodType.NumIn()-1 {
	// Non-variadic args
	if !m.Matches(args[i]) {
	return fmt.Errorf("expected call at %s doesn't match the argument at index %s.\nGot: %v\nWant: %v",
	c.origin, strconv.Itoa(i), formatGottenArg(m, args[i]), m)
	}
	continue
	}
	// The last arg has a possibility of a variadic argument, so let it branch

	// sample: Foo(a int, b int, c ...int)
	if i < len(c.args) && i < len(args) {
	if m.Matches(args[i]) {
	// Got Foo(a, b, c) want Foo(matcherA, matcherB, gomock.Any())
	// Got Foo(a, b, c) want Foo(matcherA, matcherB, someSliceMatcher)
	// Got Foo(a, b, c) want Foo(matcherA, matcherB, matcherC)
	// Got Foo(a, b) want Foo(matcherA, matcherB)
	// Got Foo(a, b, c, d) want Foo(matcherA, matcherB, matcherC, matcherD)
	continue
	}
	}

	// The number of actual args don't match the number of matchers,
	// or the last matcher is a slice and the last arg is not.
	// If this function still matches it is because the last matcher
	// matches all the remaining arguments or the lack of any.
	// Convert the remaining arguments, if any, into a slice of the
	// expected type.
	vArgsType := c.methodType.In(c.methodType.NumIn() - 1)
	vArgs := reflect.MakeSlice(vArgsType, 0, len(args)-i)
	for _, arg := range args[i:] {
	vArgs = reflect.Append(vArgs, reflect.ValueOf(arg))
	}
	if m.Matches(vArgs.Interface()) {
	// Got Foo(a, b, c, d, e) want Foo(matcherA, matcherB, gomock.Any())
	// Got Foo(a, b, c, d, e) want Foo(matcherA, matcherB, someSliceMatcher)
	// Got Foo(a, b) want Foo(matcherA, matcherB, gomock.Any())
	// Got Foo(a, b) want Foo(matcherA, matcherB, someEmptySliceMatcher)
	break
	}
	// Wrong number of matchers or not match. Fail.
	// Got Foo(a, b) want Foo(matcherA, matcherB, matcherC, matcherD)
	// Got Foo(a, b, c) want Foo(matcherA, matcherB, matcherC, matcherD)
	// Got Foo(a, b, c, d) want Foo(matcherA, matcherB, matcherC, matcherD, matcherE)
	// Got Foo(a, b, c, d, e) want Foo(matcherA, matcherB, matcherC, matcherD)
	// Got Foo(a, b, c) want Foo(matcherA, matcherB)

	return fmt.Errorf("expected call at %s doesn't match the argument at index %s.\nGot: %v\nWant: %v",
	c.origin, strconv.Itoa(i), formatGottenArg(m, args[i:]), c.args[i])
	}
	}

	// Check that all prerequisite calls have been satisfied.
	for _, preReqCall := range c.preReqs {
	if !preReqCall.satisfied() {
	return fmt.Errorf("expected call at %s doesn't have a prerequisite call satisfied:\n%v\nshould be called before:\n%v",
	c.origin, preReqCall, c)
	}
	}

	// Check that the call is not exhausted.
	if c.exhausted() {
	return fmt.Errorf("expected call at %s has already been called the max number of times", c.origin)
	}

	return nil
	}

	// dropPrereqs tells the expected Call to not re-check prerequisite calls any
	// longer, and to return its current set.
	func (c Call) dropPrereqs() (preReqs []Call) {
	preReqs = c.preReqs
	c.preReqs = nil
	return
	}

	func (c *Call) call() []func([]interface{}) []interface{} {
	c.numCalls++
	return c.actions
	}

	// InOrder declares that the given calls should occur in order.
	func InOrder(calls ...*Call) {
	for i := 1; i < len(calls); i++ {
	calls[i].After(calls[i-1])
	}
	}

	func setSlice(arg interface{}, v reflect.Value) {
	va := reflect.ValueOf(arg)
	for i := 0; i < v.Len(); i++ {
	va.Index(i).Set(v.Index(i))
	}
	}

	func (c *Call) addAction(action func([]interface{}) []interface{}) {
	c.actions = append(c.actions, action)
	}

	func formatGottenArg(m Matcher, arg interface{}) string {
	got := fmt.Sprintf("%v (%T)", arg, arg)
	if gs, ok := m.(GotFormatter); ok {
	got = gs.Got(arg)
	}
	return got
	}