diff --git a/src/archive/zip/zip_test.go b/src/archive/zip/zip_test.go
index 5adb87d5e3..50218a2bbd 100644
--- a/src/archive/zip/zip_test.go
+++ b/src/archive/zip/zip_test.go
@@ -15,6 +15,7 @@ import (
 	"internal/testenv"
 	"io"
 	"io/ioutil"
+	"runtime"
 	"sort"
 	"strings"
 	"testing"
@@ -461,6 +462,9 @@ func suffixIsZip64(t *testing.T, zip sizedReaderAt) bool {
 
 // Zip64 is required if the total size of the records is uint32max.
 func TestZip64LargeDirectory(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("too slow on wasm")
+	}
 	if testing.Short() {
 		t.Skip("skipping in short mode")
 	}
diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index f534657055..19e4116eb3 100644
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -48,7 +48,7 @@ func tooSlow(t *testing.T) {
 
 func init() {
 	switch runtime.GOOS {
-	case "android", "nacl":
+	case "android", "js", "nacl":
 		canRun = false
 	case "darwin":
 		switch runtime.GOARCH {
diff --git a/src/cmd/go/internal/base/signal_unix.go b/src/cmd/go/internal/base/signal_unix.go
index 4ca3da9922..38490b571b 100644
--- a/src/cmd/go/internal/base/signal_unix.go
+++ b/src/cmd/go/internal/base/signal_unix.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
+// +build darwin dragonfly freebsd js linux nacl netbsd openbsd solaris
 
 package base
 
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch_test.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch_test.go
index f15328bfae..afb135b7cd 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch_test.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch_test.go
@@ -361,7 +361,7 @@ func closedError() string {
 }
 
 func TestHttpsInsecure(t *testing.T) {
-	if runtime.GOOS == "nacl" {
+	if runtime.GOOS == "nacl" || runtime.GOOS == "js" {
 		t.Skip("test assumes tcp available")
 	}
 	saveHome := os.Getenv(homeEnv())
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui_test.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui_test.go
index 7e061699ce..328f1596d9 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui_test.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui_test.go
@@ -237,7 +237,7 @@ func makeFakeProfile() *profile.Profile {
 }
 
 func TestGetHostAndPort(t *testing.T) {
-	if runtime.GOOS == "nacl" {
+	if runtime.GOOS == "nacl" || runtime.GOOS == "js" {
 		t.Skip("test assumes tcp available")
 	}
 
diff --git a/src/debug/elf/file_test.go b/src/debug/elf/file_test.go
index 880b66e797..11d8992b71 100644
--- a/src/debug/elf/file_test.go
+++ b/src/debug/elf/file_test.go
@@ -784,7 +784,7 @@ func TestCompressedSection(t *testing.T) {
 func TestNoSectionOverlaps(t *testing.T) {
 	// Ensure cmd/link outputs sections without overlaps.
 	switch runtime.GOOS {
-	case "android", "darwin", "nacl", "plan9", "windows":
+	case "android", "darwin", "js", "nacl", "plan9", "windows":
 		t.Skipf("cmd/link doesn't produce ELF binaries on %s", runtime.GOOS)
 	}
 	_ = net.ResolveIPAddr // force dynamic linkage
diff --git a/src/encoding/gob/encoder_test.go b/src/encoding/gob/encoder_test.go
index a1ca252ccd..a41fc9e889 100644
--- a/src/encoding/gob/encoder_test.go
+++ b/src/encoding/gob/encoder_test.go
@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"reflect"
+	"runtime"
 	"strings"
 	"testing"
 )
@@ -1130,6 +1131,9 @@ func TestBadData(t *testing.T) {
 
 // TestHugeWriteFails tests that enormous messages trigger an error.
 func TestHugeWriteFails(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("out of memory on wasm")
+	}
 	if testing.Short() {
 		// Requires allocating a monster, so don't do this from all.bash.
 		t.Skip("skipping huge allocation in short mode")
diff --git a/src/internal/testenv/testenv.go b/src/internal/testenv/testenv.go
index b3c16a8e87..8f69fe0da5 100644
--- a/src/internal/testenv/testenv.go
+++ b/src/internal/testenv/testenv.go
@@ -41,7 +41,7 @@ func HasGoBuild() bool {
 		return false
 	}
 	switch runtime.GOOS {
-	case "android", "nacl":
+	case "android", "nacl", "js":
 		return false
 	case "darwin":
 		if strings.HasPrefix(runtime.GOARCH, "arm") {
@@ -114,7 +114,7 @@ func GoTool() (string, error) {
 // using os.StartProcess or (more commonly) exec.Command.
 func HasExec() bool {
 	switch runtime.GOOS {
-	case "nacl":
+	case "nacl", "js":
 		return false
 	case "darwin":
 		if strings.HasPrefix(runtime.GOARCH, "arm") {
@@ -149,13 +149,16 @@ func MustHaveExec(t testing.TB) {
 // HasExternalNetwork reports whether the current system can use
 // external (non-localhost) networks.
 func HasExternalNetwork() bool {
-	return !testing.Short()
+	return !testing.Short() && runtime.GOOS != "nacl" && runtime.GOOS != "js"
 }
 
 // MustHaveExternalNetwork checks that the current system can use
 // external (non-localhost) networks.
 // If not, MustHaveExternalNetwork calls t.Skip with an explanation.
 func MustHaveExternalNetwork(t testing.TB) {
+	if runtime.GOOS == "nacl" || runtime.GOOS == "js" {
+		t.Skipf("skipping test: no external network on %s", runtime.GOOS)
+	}
 	if testing.Short() {
 		t.Skipf("skipping test: no external network in -short mode")
 	}
diff --git a/src/log/syslog/syslog_test.go b/src/log/syslog/syslog_test.go
index 1263be6d78..6da3edd555 100644
--- a/src/log/syslog/syslog_test.go
+++ b/src/log/syslog/syslog_test.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !windows,!nacl,!plan9
+// +build !windows,!nacl,!plan9,!js
 
 package syslog
 
diff --git a/src/runtime/chanbarrier_test.go b/src/runtime/chanbarrier_test.go
index b6029fb044..d4795748bf 100644
--- a/src/runtime/chanbarrier_test.go
+++ b/src/runtime/chanbarrier_test.go
@@ -57,7 +57,7 @@ func testChanSendBarrier(useSelect bool) {
 	var globalMu sync.Mutex
 	outer := 100
 	inner := 100000
-	if testing.Short() {
+	if testing.Short() || runtime.GOARCH == "wasm" {
 		outer = 10
 		inner = 1000
 	}
diff --git a/src/runtime/crash_nonunix_test.go b/src/runtime/crash_nonunix_test.go
index 2ce995c069..bf349a5d89 100644
--- a/src/runtime/crash_nonunix_test.go
+++ b/src/runtime/crash_nonunix_test.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build windows plan9 nacl
+// +build windows plan9 nacl js,wasm
 
 package runtime_test
 
diff --git a/src/runtime/gc_test.go b/src/runtime/gc_test.go
index 561061e3d8..d683d89fe4 100644
--- a/src/runtime/gc_test.go
+++ b/src/runtime/gc_test.go
@@ -155,6 +155,10 @@ func TestHugeGCInfo(t *testing.T) {
 }
 
 func TestPeriodicGC(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("no sysmon on wasm yet")
+	}
+
 	// Make sure we're not in the middle of a GC.
 	runtime.GC()
 
diff --git a/src/runtime/hash_test.go b/src/runtime/hash_test.go
index 1400579cda..7b8ebc4f3c 100644
--- a/src/runtime/hash_test.go
+++ b/src/runtime/hash_test.go
@@ -161,6 +161,9 @@ func TestSmhasherZeros(t *testing.T) {
 
 // Strings with up to two nonzero bytes all have distinct hashes.
 func TestSmhasherTwoNonzero(t *testing.T) {
+	if GOARCH == "wasm" {
+		t.Skip("Too slow on wasm")
+	}
 	if testing.Short() {
 		t.Skip("Skipping in short mode")
 	}
@@ -229,6 +232,9 @@ func TestSmhasherCyclic(t *testing.T) {
 
 // Test strings with only a few bits set
 func TestSmhasherSparse(t *testing.T) {
+	if GOARCH == "wasm" {
+		t.Skip("Too slow on wasm")
+	}
 	if testing.Short() {
 		t.Skip("Skipping in short mode")
 	}
@@ -264,6 +270,9 @@ func setbits(h *HashSet, b []byte, i int, k int) {
 // Test all possible combinations of n blocks from the set s.
 // "permutation" is a bad name here, but it is what Smhasher uses.
 func TestSmhasherPermutation(t *testing.T) {
+	if GOARCH == "wasm" {
+		t.Skip("Too slow on wasm")
+	}
 	if testing.Short() {
 		t.Skip("Skipping in short mode")
 	}
@@ -433,6 +442,9 @@ func (k *IfaceKey) name() string {
 
 // Flipping a single bit of a key should flip each output bit with 50% probability.
 func TestSmhasherAvalanche(t *testing.T) {
+	if GOARCH == "wasm" {
+		t.Skip("Too slow on wasm")
+	}
 	if testing.Short() {
 		t.Skip("Skipping in short mode")
 	}
@@ -508,6 +520,9 @@ func TestSmhasherWindowed(t *testing.T) {
 	windowed(t, &BytesKey{make([]byte, 128)})
 }
 func windowed(t *testing.T, k Key) {
+	if GOARCH == "wasm" {
+		t.Skip("Too slow on wasm")
+	}
 	if testing.Short() {
 		t.Skip("Skipping in short mode")
 	}
diff --git a/src/runtime/pprof/pprof_test.go b/src/runtime/pprof/pprof_test.go
index 96fcfc9703..e8567f4952 100644
--- a/src/runtime/pprof/pprof_test.go
+++ b/src/runtime/pprof/pprof_test.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !nacl
+// +build !nacl,!js
 
 package pprof
 
diff --git a/src/runtime/proc_test.go b/src/runtime/proc_test.go
index 2ece829071..ad325987ac 100644
--- a/src/runtime/proc_test.go
+++ b/src/runtime/proc_test.go
@@ -28,6 +28,9 @@ func perpetuumMobile() {
 }
 
 func TestStopTheWorldDeadlock(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("no preemption on wasm yet")
+	}
 	if testing.Short() {
 		t.Skip("skipping during short test")
 	}
@@ -230,6 +233,10 @@ func TestBlockLocked(t *testing.T) {
 }
 
 func TestTimerFairness(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("no preemption on wasm yet")
+	}
+
 	done := make(chan bool)
 	c := make(chan bool)
 	for i := 0; i < 2; i++ {
@@ -256,6 +263,10 @@ func TestTimerFairness(t *testing.T) {
 }
 
 func TestTimerFairness2(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("no preemption on wasm yet")
+	}
+
 	done := make(chan bool)
 	c := make(chan bool)
 	for i := 0; i < 2; i++ {
@@ -290,6 +301,10 @@ var preempt = func() int {
 }
 
 func TestPreemption(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("no preemption on wasm yet")
+	}
+
 	// Test that goroutines are preempted at function calls.
 	N := 5
 	if testing.Short() {
@@ -313,6 +328,10 @@ func TestPreemption(t *testing.T) {
 }
 
 func TestPreemptionGC(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("no preemption on wasm yet")
+	}
+
 	// Test that pending GC preempts running goroutines.
 	P := 5
 	N := 10
@@ -385,6 +404,9 @@ func TestNumGoroutine(t *testing.T) {
 }
 
 func TestPingPongHog(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("no preemption on wasm yet")
+	}
 	if testing.Short() {
 		t.Skip("skipping in -short mode")
 	}
@@ -834,6 +856,10 @@ func TestStealOrder(t *testing.T) {
 }
 
 func TestLockOSThreadNesting(t *testing.T) {
+	if runtime.GOARCH == "wasm" {
+		t.Skip("no threads on wasm yet")
+	}
+
 	go func() {
 		e, i := runtime.LockOSCounts()
 		if e != 0 || i != 0 {
diff --git a/src/runtime/runtime_test.go b/src/runtime/runtime_test.go
index d5b6b3ac3c..8263d4059a 100644
--- a/src/runtime/runtime_test.go
+++ b/src/runtime/runtime_test.go
@@ -169,6 +169,9 @@ func testSetPanicOnFault(t *testing.T, addr uintptr, nfault *int) {
 	if GOOS == "nacl" {
 		t.Skip("nacl doesn't seem to fault on high addresses")
 	}
+	if GOOS == "js" {
+		t.Skip("js does not support catching faults")
+	}
 
 	defer func() {
 		if err := recover(); err != nil {
@@ -264,7 +267,7 @@ func TestTrailingZero(t *testing.T) {
 }
 
 func TestBadOpen(t *testing.T) {
-	if GOOS == "windows" || GOOS == "nacl" {
+	if GOOS == "windows" || GOOS == "nacl" || GOOS == "js" {
 		t.Skip("skipping OS that doesn't have open/read/write/close")
 	}
 	// make sure we get the correct error code if open fails. Same for
diff --git a/src/runtime/rwmutex_test.go b/src/runtime/rwmutex_test.go
index 872b3b098e..291a32ea5e 100644
--- a/src/runtime/rwmutex_test.go
+++ b/src/runtime/rwmutex_test.go
@@ -47,6 +47,9 @@ func doTestParallelReaders(numReaders int) {
 }
 
 func TestParallelRWMutexReaders(t *testing.T) {
+	if GOARCH == "wasm" {
+		t.Skip("wasm has no threads yet")
+	}
 	defer GOMAXPROCS(GOMAXPROCS(-1))
 	// If runtime triggers a forced GC during this test then it will deadlock,
 	// since the goroutines can't be stopped/preempted.
diff --git a/src/runtime/stack_test.go b/src/runtime/stack_test.go
index 91d10bad5c..81a637ccb3 100644
--- a/src/runtime/stack_test.go
+++ b/src/runtime/stack_test.go
@@ -76,6 +76,10 @@ func TestStackMem(t *testing.T) {
 
 // Test stack growing in different contexts.
 func TestStackGrowth(t *testing.T) {
+	if GOARCH == "wasm" {
+		t.Skip("fails on wasm (too slow?)")
+	}
+
 	// Don't make this test parallel as this makes the 20 second
 	// timeout unreliable on slow builders. (See issue #19381.)
 
diff --git a/src/syscall/syscall_test.go b/src/syscall/syscall_test.go
index c3fffda2df..2a9d90e64c 100644
--- a/src/syscall/syscall_test.go
+++ b/src/syscall/syscall_test.go
@@ -62,8 +62,8 @@ func TestExecErrPermutedFds(t *testing.T) {
 }
 
 func TestGettimeofday(t *testing.T) {
-	if runtime.GOOS == "nacl" {
-		t.Skip("not implemented on nacl")
+	if runtime.GOOS == "nacl" || runtime.GOOS == "js" {
+		t.Skip("not implemented on " + runtime.GOOS)
 	}
 	tv := &syscall.Timeval{}
 	if err := syscall.Gettimeofday(tv); err != nil {
diff --git a/src/text/template/exec.go b/src/text/template/exec.go
index 916be46b86..8f8b5fe218 100644
--- a/src/text/template/exec.go
+++ b/src/text/template/exec.go
@@ -19,7 +19,14 @@ import (
 // templates. This limit is only practically reached by accidentally
 // recursive template invocations. This limit allows us to return
 // an error instead of triggering a stack overflow.
-const maxExecDepth = 100000
+var maxExecDepth = initMaxExecDepth()
+
+func initMaxExecDepth() int {
+	if runtime.GOARCH == "wasm" {
+		return 1000
+	}
+	return 100000
+}
 
 // state represents the state of an execution. It's not part of the
 // template so that multiple executions of the same template
diff --git a/test/fixedbugs/bug248.go b/test/fixedbugs/bug248.go
index 30f2ce48f1..a61620f23f 100644
--- a/test/fixedbugs/bug248.go
+++ b/test/fixedbugs/bug248.go
@@ -1,4 +1,4 @@
-// +build !nacl,!plan9,!windows
+// +build !nacl,!js,!plan9,!windows
 // run
 
 // Copyright 2009 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/bug302.go b/test/fixedbugs/bug302.go
index e4de25d5d0..c763b87786 100644
--- a/test/fixedbugs/bug302.go
+++ b/test/fixedbugs/bug302.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2010 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/bug345.go b/test/fixedbugs/bug345.go
index 59e99c7d2a..af505c8a3b 100644
--- a/test/fixedbugs/bug345.go
+++ b/test/fixedbugs/bug345.go
@@ -1,4 +1,4 @@
-// +build !nacl,!plan9,!windows
+// +build !nacl,!js,!plan9,!windows
 // run
 
 // Copyright 2011 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/bug369.go b/test/fixedbugs/bug369.go
index 60162ab1cb..e2a1147735 100644
--- a/test/fixedbugs/bug369.go
+++ b/test/fixedbugs/bug369.go
@@ -1,4 +1,4 @@
-// +build !nacl,!windows
+// +build !nacl,!js,!windows
 // run
 
 // Copyright 2011 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/bug429_run.go b/test/fixedbugs/bug429_run.go
index 284033d1f7..c6a02aae5e 100644
--- a/test/fixedbugs/bug429_run.go
+++ b/test/fixedbugs/bug429_run.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2014 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/issue10958.go b/test/fixedbugs/issue10958.go
index 2b76694138..52487fb9bd 100644
--- a/test/fixedbugs/issue10958.go
+++ b/test/fixedbugs/issue10958.go
@@ -1,4 +1,4 @@
-// +build !nacl,disabled_see_issue_18589
+// +build !nacl,!js,disabled_see_issue_18589
 // buildrun -t 10  -gcflags=-d=ssa/insert_resched_checks/on,ssa/check/on
 
 // Copyright 2016 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/issue11656.go b/test/fixedbugs/issue11656.go
index c04a66202b..451ae6348f 100644
--- a/test/fixedbugs/issue11656.go
+++ b/test/fixedbugs/issue11656.go
@@ -9,6 +9,9 @@
 // doesn't go into the Go runtime.
 // +build !windows
 
+// wasm does not work, because the linear memory is not executable.
+// +build !wasm
+
 package main
 
 import (
diff --git a/test/fixedbugs/issue11771.go b/test/fixedbugs/issue11771.go
index d91fc5d966..99d7060d44 100644
--- a/test/fixedbugs/issue11771.go
+++ b/test/fixedbugs/issue11771.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2015 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/issue14636.go b/test/fixedbugs/issue14636.go
index 7d1b606241..6b342e4029 100644
--- a/test/fixedbugs/issue14636.go
+++ b/test/fixedbugs/issue14636.go
@@ -1,4 +1,4 @@
-// +build !nacl,!android,!darwin darwin,!arm
+// +build !nacl,!js,!android,!darwin darwin,!arm
 // run
 
 // Copyright 2016 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/issue16037_run.go b/test/fixedbugs/issue16037_run.go
index 23fff5925b..d05e3f7f31 100644
--- a/test/fixedbugs/issue16037_run.go
+++ b/test/fixedbugs/issue16037_run.go
@@ -1,4 +1,4 @@
-// +build !nacl,!android
+// +build !nacl,!js,!android
 // run
 
 // Copyright 2016 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/issue18902.go b/test/fixedbugs/issue18902.go
index 78c92187ee..9261ce7073 100644
--- a/test/fixedbugs/issue18902.go
+++ b/test/fixedbugs/issue18902.go
@@ -1,5 +1,5 @@
 // run
-// +build !nacl
+// +build !nacl,!js
 
 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue19182.go b/test/fixedbugs/issue19182.go
index 3a90ff4b26..e1f3ffb474 100644
--- a/test/fixedbugs/issue19182.go
+++ b/test/fixedbugs/issue19182.go
@@ -1,4 +1,5 @@
 // run
+// +build !js
 
 // Copyright 2017 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue19658.go b/test/fixedbugs/issue19658.go
index 91cb88658e..b2539629df 100644
--- a/test/fixedbugs/issue19658.go
+++ b/test/fixedbugs/issue19658.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2017 The Go Authors. All rights reserved.
diff --git a/test/fixedbugs/issue21317.go b/test/fixedbugs/issue21317.go
index ae0e0b55f9..530694af12 100644
--- a/test/fixedbugs/issue21317.go
+++ b/test/fixedbugs/issue21317.go
@@ -21,7 +21,7 @@ import (
 )
 
 func main() {
-	if runtime.Compiler != "gc" || runtime.GOOS == "nacl" {
+	if runtime.Compiler != "gc" || runtime.GOOS == "nacl" || runtime.GOOS == "js" {
 		return
 	}
 
diff --git a/test/fixedbugs/issue22660.go b/test/fixedbugs/issue22660.go
index 48686fefee..b2282ea665 100644
--- a/test/fixedbugs/issue22660.go
+++ b/test/fixedbugs/issue22660.go
@@ -19,7 +19,7 @@ import (
 )
 
 func main() {
-	if runtime.GOOS == "nacl" {
+	if runtime.GOOS == "nacl" || runtime.GOOS == "js" {
 		return // no file system available on builders
 	}
 
diff --git a/test/fixedbugs/issue22662b.go b/test/fixedbugs/issue22662b.go
index 42c2a806d7..3594c0f4ef 100644
--- a/test/fixedbugs/issue22662b.go
+++ b/test/fixedbugs/issue22662b.go
@@ -36,8 +36,8 @@ var tests = []struct {
 }
 
 func main() {
-	if runtime.GOOS == "nacl" {
-		return // no file system available on builders
+	if runtime.GOOS == "nacl" || runtime.GOOS == "js" {
+		return // can not exec go tool
 	}
 
 	f, err := ioutil.TempFile("", "issue22662b.go")
diff --git a/test/fixedbugs/issue9355.go b/test/fixedbugs/issue9355.go
index 10f8c73069..9657e64491 100644
--- a/test/fixedbugs/issue9355.go
+++ b/test/fixedbugs/issue9355.go
@@ -16,7 +16,7 @@ import (
 )
 
 func main() {
-	if runtime.Compiler != "gc" || runtime.GOOS == "nacl" {
+	if runtime.Compiler != "gc" || runtime.GOOS == "nacl" || runtime.GOOS == "js" {
 		return
 	}
 
diff --git a/test/fixedbugs/issue9604b.go b/test/fixedbugs/issue9604b.go
index ebbd205baf..d32116b857 100644
--- a/test/fixedbugs/issue9604b.go
+++ b/test/fixedbugs/issue9604b.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// terribly slow on wasm
+// +build !wasm
+
 package main
 
 import (
diff --git a/test/fixedbugs/issue9862_run.go b/test/fixedbugs/issue9862_run.go
index be22f40580..299e809545 100644
--- a/test/fixedbugs/issue9862_run.go
+++ b/test/fixedbugs/issue9862_run.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2015 The Go Authors. All rights reserved.
diff --git a/test/gc2.go b/test/gc2.go
index 31b36d8a08..2f8eb9b70e 100644
--- a/test/gc2.go
+++ b/test/gc2.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2011 The Go Authors. All rights reserved.
diff --git a/test/linkmain_run.go b/test/linkmain_run.go
index 55de481a81..68d53e8cad 100644
--- a/test/linkmain_run.go
+++ b/test/linkmain_run.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2014 The Go Authors. All rights reserved.
diff --git a/test/linkobj.go b/test/linkobj.go
index 8a86aa872f..2902d23f4b 100644
--- a/test/linkobj.go
+++ b/test/linkobj.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2016 The Go Authors. All rights reserved.
diff --git a/test/linkx_run.go b/test/linkx_run.go
index cc249c9cfc..ca9d31612a 100644
--- a/test/linkx_run.go
+++ b/test/linkx_run.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2014 The Go Authors. All rights reserved.
diff --git a/test/live_syscall.go b/test/live_syscall.go
index 6d954653cc..65a161c028 100644
--- a/test/live_syscall.go
+++ b/test/live_syscall.go
@@ -1,6 +1,6 @@
 // errorcheck -0 -m -live
 
-// +build !windows
+// +build !windows,!js
 
 // Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/nilptr3.go b/test/nilptr3.go
index 9a96bb5386..a22e60ef11 100644
--- a/test/nilptr3.go
+++ b/test/nilptr3.go
@@ -1,5 +1,7 @@
 // errorcheck -0 -d=nil
 
+// +build !wasm
+
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/test/nilptr3_wasm.go b/test/nilptr3_wasm.go
new file mode 100644
index 0000000000..9376d42097
--- /dev/null
+++ b/test/nilptr3_wasm.go
@@ -0,0 +1,270 @@
+// errorcheck -0 -d=nil
+
+// +build wasm
+
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test that nil checks are removed.
+// Optimization is enabled.
+
+package p
+
+type Struct struct {
+	X int
+	Y float64
+}
+
+type BigStruct struct {
+	X int
+	Y float64
+	A [1 << 20]int
+	Z string
+}
+
+type Empty struct {
+}
+
+type Empty1 struct {
+	Empty
+}
+
+var (
+	intp       *int
+	arrayp     *[10]int
+	array0p    *[0]int
+	bigarrayp  *[1 << 26]int
+	structp    *Struct
+	bigstructp *BigStruct
+	emptyp     *Empty
+	empty1p    *Empty1
+)
+
+func f1() {
+	_ = *intp // ERROR "generated nil check"
+
+	// This one should be removed but the block copy needs
+	// to be turned into its own pseudo-op in order to see
+	// the indirect.
+	_ = *arrayp // ERROR "generated nil check"
+
+	// 0-byte indirect doesn't suffice.
+	// we don't registerize globals, so there are no removed.* nil checks.
+	_ = *array0p // ERROR "generated nil check"
+	_ = *array0p // ERROR "removed nil check"
+
+	_ = *intp    // ERROR "removed nil check"
+	_ = *arrayp  // ERROR "removed nil check"
+	_ = *structp // ERROR "generated nil check"
+	_ = *emptyp  // ERROR "generated nil check"
+	_ = *arrayp  // ERROR "removed nil check"
+}
+
+func f2() {
+	var (
+		intp       *int
+		arrayp     *[10]int
+		array0p    *[0]int
+		bigarrayp  *[1 << 20]int
+		structp    *Struct
+		bigstructp *BigStruct
+		emptyp     *Empty
+		empty1p    *Empty1
+	)
+
+	_ = *intp       // ERROR "generated nil check"
+	_ = *arrayp     // ERROR "generated nil check"
+	_ = *array0p    // ERROR "generated nil check"
+	_ = *array0p    // ERROR "removed.* nil check"
+	_ = *intp       // ERROR "removed.* nil check"
+	_ = *arrayp     // ERROR "removed.* nil check"
+	_ = *structp    // ERROR "generated nil check"
+	_ = *emptyp     // ERROR "generated nil check"
+	_ = *arrayp     // ERROR "removed.* nil check"
+	_ = *bigarrayp  // ERROR "generated nil check" ARM removed nil check before indirect!!
+	_ = *bigstructp // ERROR "generated nil check"
+	_ = *empty1p    // ERROR "generated nil check"
+}
+
+func fx10k() *[10000]int
+
+var b bool
+
+func f3(x *[10000]int) {
+	// Using a huge type and huge offsets so the compiler
+	// does not expect the memory hardware to fault.
+	_ = x[9999] // ERROR "generated nil check"
+
+	for {
+		if x[9999] != 0 { // ERROR "removed nil check"
+			break
+		}
+	}
+
+	x = fx10k()
+	_ = x[9999] // ERROR "generated nil check"
+	if b {
+		_ = x[9999] // ERROR "removed.* nil check"
+	} else {
+		_ = x[9999] // ERROR "removed.* nil check"
+	}
+	_ = x[9999] // ERROR "removed nil check"
+
+	x = fx10k()
+	if b {
+		_ = x[9999] // ERROR "generated nil check"
+	} else {
+		_ = x[9999] // ERROR "generated nil check"
+	}
+	_ = x[9999] // ERROR "generated nil check"
+
+	fx10k()
+	// This one is a bit redundant, if we figured out that
+	// x wasn't going to change across the function call.
+	// But it's a little complex to do and in practice doesn't
+	// matter enough.
+	_ = x[9999] // ERROR "removed nil check"
+}
+
+func f3a() {
+	x := fx10k()
+	y := fx10k()
+	z := fx10k()
+	_ = &x[9] // ERROR "generated nil check"
+	y = z
+	_ = &x[9] // ERROR "removed.* nil check"
+	x = y
+	_ = &x[9] // ERROR "generated nil check"
+}
+
+func f3b() {
+	x := fx10k()
+	y := fx10k()
+	_ = &x[9] // ERROR "generated nil check"
+	y = x
+	_ = &x[9] // ERROR "removed.* nil check"
+	x = y
+	_ = &x[9] // ERROR "removed.* nil check"
+}
+
+func fx10() *[10]int
+
+func f4(x *[10]int) {
+	// Most of these have no checks because a real memory reference follows,
+	// and the offset is small enough that if x is nil, the address will still be
+	// in the first unmapped page of memory.
+
+	_ = x[9] // ERROR "generated nil check" // bug: would like to remove this check (but nilcheck and load are in different blocks)
+
+	for {
+		if x[9] != 0 { // ERROR "removed nil check"
+			break
+		}
+	}
+
+	x = fx10()
+	_ = x[9] // ERROR "generated nil check" // bug would like to remove before indirect
+	if b {
+		_ = x[9] // ERROR "removed nil check"
+	} else {
+		_ = x[9] // ERROR "removed nil check"
+	}
+	_ = x[9] // ERROR "removed nil check"
+
+	x = fx10()
+	if b {
+		_ = x[9] // ERROR "generated nil check"  // bug would like to remove before indirect
+	} else {
+		_ = &x[9] // ERROR "generated nil check"
+	}
+	_ = x[9] // ERROR "generated nil check"  // bug would like to remove before indirect
+
+	fx10()
+	_ = x[9] // ERROR "removed nil check"
+
+	x = fx10()
+	y := fx10()
+	_ = &x[9] // ERROR "generated nil check"
+	y = x
+	_ = &x[9] // ERROR "removed[a-z ]* nil check"
+	x = y
+	_ = &x[9] // ERROR "removed[a-z ]* nil check"
+}
+
+func f5(p *float32, q *float64, r *float32, s *float64) float64 {
+	x := float64(*p) // ERROR "generated nil check"
+	y := *q          // ERROR "generated nil check"
+	*r = 7           // ERROR "generated nil check"
+	*s = 9           // ERROR "generated nil check"
+	return x + y
+}
+
+type T [29]byte
+
+func f6(p, q *T) {
+	x := *p // ERROR "generated nil check"
+	*q = x  // ERROR "generated nil check"
+}
+
+func m1(m map[int][80]byte) byte {
+	v := m[3] // ERROR "removed nil check"
+	return v[5]
+}
+func m2(m map[int][800]byte) byte {
+	v := m[3] // ERROR "removed nil check"
+	return v[5]
+}
+func m3(m map[int][80]byte) (byte, bool) {
+	v, ok := m[3] // ERROR "removed nil check"
+	return v[5], ok
+}
+func m4(m map[int][800]byte) (byte, bool) {
+	v, ok := m[3] // ERROR "removed nil check"
+	return v[5], ok
+}
+func p1() byte {
+	p := new([100]byte)
+	return p[5] // ERROR "removed nil check"
+}
+
+// make sure not to do nil check for access of PAUTOHEAP
+//go:noinline
+func (p *Struct) m() {}
+func c1() {
+	var x Struct
+	func() { x.m() }() // ERROR "removed nil check"
+}
+
+type SS struct {
+	x byte
+}
+
+type TT struct {
+	SS
+}
+
+func f(t *TT) *byte {
+	// See issue 17242.
+	s := &t.SS  // ERROR "removed nil check"
+	return &s.x // ERROR "generated nil check"
+}
+
+// make sure not to do nil check for newobject
+func f7() (*Struct, float64) {
+	t := new(Struct)
+	p := &t.Y    // ERROR "removed nil check"
+	return t, *p // ERROR "removed nil check"
+}
+
+// make sure to remove nil check for memory move (issue #18003)
+func f8(t *[8]int) [8]int {
+	return *t // ERROR "generated nil check"
+}
+
+func f9() []int {
+	x := new([1]int)
+	x[0] = 1  // ERROR "removed nil check"
+	y := x[:] // ERROR "removed nil check"
+	return y
+}
diff --git a/test/nosplit.go b/test/nosplit.go
index e6cecebde3..e6cd04e563 100644
--- a/test/nosplit.go
+++ b/test/nosplit.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2014 The Go Authors. All rights reserved.
diff --git a/test/peano.go b/test/peano.go
index 745f5153f6..1102a97244 100644
--- a/test/peano.go
+++ b/test/peano.go
@@ -9,6 +9,8 @@
 
 package main
 
+import "runtime"
+
 type Number *Number
 
 // -------------------------------------
@@ -116,7 +118,11 @@ var results = [...]int{
 }
 
 func main() {
-	for i := 0; i <= 9; i++ {
+	max := 9
+	if runtime.GOARCH == "wasm" {
+		max = 7 // stack size is limited
+	}
+	for i := 0; i <= max; i++ {
 		if f := count(fact(gen(i))); f != results[i] {
 			println("FAIL:", i, "!:", f, "!=", results[i])
 			panic(0)
diff --git a/test/sinit_run.go b/test/sinit_run.go
index c9afd3b777..fdd19c492f 100644
--- a/test/sinit_run.go
+++ b/test/sinit_run.go
@@ -1,4 +1,4 @@
-// +build !nacl
+// +build !nacl,!js
 // run
 
 // Copyright 2014 The Go Authors. All rights reserved.