# TODO(jayconrod): support shared memory on more platforms.
[!darwin] [!linux] [!windows] skip

[short] skip

# We clean the fuzz cache during this test. Don't clean the user's cache.
env GOCACHE=$WORK/gocache

# Test that fuzzminimizetime cannot be negative seconds
! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=10000x -fuzzminimizetime=-1ms minimizer_test.go
! stdout '^ok'
! stdout 'contains a non-zero byte'
stdout 'invalid duration'
stdout FAIL

# Test that fuzzminimizetime cannot be negative times
! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=10000x -fuzzminimizetime=-1x minimizer_test.go
! stdout '^ok'
! stdout 'contains a non-zero byte'
stdout 'invalid count'
stdout FAIL

# Test that fuzzminimizetime can be zero seconds, and minimization is disabled
! go test -fuzz=FuzzMinimizeZeroDurationSet -run=FuzzMinimizeZeroDurationSet -fuzztime=10000x -fuzzminimizetime=0s minimizer_test.go
! stdout '^ok'
! stdout 'minimizing'
stdout 'there was an Error'
stdout FAIL

# Test that fuzzminimizetime can be zero times, and minimization is disabled
! go test -fuzz=FuzzMinimizeZeroLimitSet -run=FuzzMinimizeZeroLimitSet -fuzztime=10000x -fuzzminimizetime=0x minimizer_test.go
! stdout '^ok'
! stdout 'minimizing'
stdout 'there was an Error'
stdout FAIL

# Test that minimization is working for recoverable errors.
! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=10000x minimizer_test.go
! stdout '^ok'
stdout 'got the minimum size!'
stdout 'contains a non-zero byte'
stdout FAIL

# Check that the bytes written to testdata are of length 50 (the minimum size)
go run check_testdata.go FuzzMinimizerRecoverable 50

# Test that re-running the minimized value causes a crash.
! go test -run=FuzzMinimizerRecoverable minimizer_test.go
rm testdata

# Test that minimization doesn't run for non-recoverable errors.
! go test -fuzz=FuzzMinimizerNonrecoverable -run=FuzzMinimizerNonrecoverable -fuzztime=10000x minimizer_test.go
! stdout '^ok'
! stdout 'minimizing'
stdout 'fuzzing process terminated unexpectedly: exit status 99'
stdout FAIL

# Check that re-running the value causes a crash.
! go test -run=FuzzMinimizerNonrecoverable minimizer_test.go
rm testdata

# Clear the fuzzing cache. There may already be minimized inputs that would
# interfere with the next stage of the test.
go clean -fuzzcache

# Test that minimization can be cancelled by fuzzminimizetime and the latest
# crash will still be logged and written to testdata.
! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=100x -fuzzminimizetime=1x minimizer_test.go
! stdout '^ok'
stdout 'testdata[/\\]fuzz[/\\]FuzzMinimizerRecoverable[/\\]'
! stdout 'got the minimum size!'  # it shouldn't have had enough time to minimize it
stdout FAIL

# Test that re-running the unminimized value causes a crash.
! go test -run=FuzzMinimizerRecoverable minimizer_test.go

! go test -fuzz=FuzzMinimizerTooSlow -run=FuzzMinimizerTooSlow -fuzzminimizetime=3s minimizer_test.go
stdout 'fuzz: minimizing'
stdout 'fuzz: elapsed: 3s, minimizing'
stdout 'testdata[/\\]fuzz[/\\]FuzzMinimizerTooSlow[/\\]'
stdout FAIL

# TODO(jayconrod,katiehockman): add a test which verifies that the right bytes
# are written to testdata in the case of an interrupt during minimization.

-- go.mod --
module m

go 1.16
-- minimizer_test.go --
package fuzz_test

import (
	"os"
	"testing"
	"time"
)

func FuzzMinimizeZeroDurationSet(f *testing.F) {
	f.Fuzz(func(t *testing.T, b []byte) {
		if len(b) > 5 {
			t.Errorf("there was an Error")
		}
	})
}

func FuzzMinimizeZeroLimitSet(f *testing.F) {
	f.Fuzz(func(t *testing.T, b []byte) {
		if len(b) > 5 {
			t.Errorf("there was an Error")
		}
	})
}

func FuzzMinimizerRecoverable(f *testing.F) {
	f.Add(make([]byte, 100))
	f.Fuzz(func(t *testing.T, b []byte) {
		if len(b) < 50 {
			// Make sure that b is large enough that it can be minimized
			return
		}
		// Given the randomness of the mutations, this should allow the
		// minimizer to trim down the value a bit.
		for _, n := range b {
			if n != 0 {
				if len(b) == 50 {
					t.Log("got the minimum size!")
				}
				t.Fatal("contains a non-zero byte")
			}
		}
	})
}

func FuzzMinimizerNonrecoverable(f *testing.F) {
	f.Add(make([]byte, 100))
	f.Fuzz(func(t *testing.T, b []byte) {
		if len(b) < 50 {
			// Make sure that b is large enough that it can be minimized
			return
		}
		// Given the randomness of the mutations, this should allow the
		// minimizer to trim down the value a bit.
		for _, n := range b {
			if n != 0 {
				t.Log("contains a non-zero byte")
				os.Exit(99)
			}
		}
	})
}

func FuzzMinimizerTooSlow(f *testing.F) {
	f.Fuzz(func(t *testing.T, b []byte) {
		if len(b) > 50 {
			t.Error("error here")
			time.Sleep(2 * time.Second)
		}
	})
}

-- check_testdata.go --
// +build ignore

package main

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strconv"
)

func main() {
	target := os.Args[1]
	numBytes, err := strconv.Atoi(os.Args[2])
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}

	// Open the file in testdata (there should only be one)
	dir := fmt.Sprintf("testdata/fuzz/%s", target)
	files, err := ioutil.ReadDir(dir)
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	if len(files) != 1 {
		fmt.Fprintf(os.Stderr, "expected one file, got %d", len(files))
		os.Exit(1)
	}
	got, err := ioutil.ReadFile(filepath.Join(dir, files[0].Name()))
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}

	// Trim the newline at the end of the file
	got = bytes.TrimSpace(got)

	// Make sure that there were exactly 100 bytes written to the corpus entry
	prefix := []byte("[]byte(")
	i := bytes.Index(got, prefix)
	gotBytes := got[i+len(prefix) : len(got)-1]
	s, err := strconv.Unquote(string(gotBytes))
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	if want, got := numBytes, len(s); want != got {
		fmt.Fprintf(os.Stderr, "want %d bytes, got %d\n", want, got)
		os.Exit(1)
	}
}