tests: migrate away from assert.Assert(err == nil)

Unfortunately, gofmt doesn't know about types so it was necessary to
find all of the err == nil statements through trial and error. Note that
there is no is.NilError, so for assert.Check(t, err == nil) we need to
switch to just doing assert.Check(t, err). If err is an error type, this
is equivalent (and there isn't another trivial way of doing it). Here
are the full set of rules used:

Generic "err == nil":

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, err == nil) -> assert.NilError(t, err)"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, err == nil) -> assert.Check(t, err)"

Generic, but with a different variable name:

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, sr.err == nil) -> assert.NilError(t, sr.err)"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, sr.err == nil) -> assert.Check(t, sr.err)"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, err2 == nil) -> assert.NilError(t, err2)"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, err2 == nil) -> assert.Check(t, err2)"

JSON-related error assertions:

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, json.Unmarshal(a, b) == nil) -> assert.NilError(t, json.Unmarshal(a, b))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, json.Unmarshal(a, b) == nil) -> assert.Check(t, json.Unmarshal(a, b))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, json.NewDecoder(a).Decode(b) == nil) -> assert.NilError(t, json.NewDecoder(a).Decode(b))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, json.NewDecoder(a).Decode(b) == nil) -> assert.Check(t, json.NewDecoder(a).Decode(b))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, json.NewEncoder(a).Encode(b) == nil) -> assert.NilError(t, json.NewEncoder(a).Encode(b))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, json.NewEncoder(a).Encode(b) == nil) -> assert.Check(t, json.NewEncoder(a).Encode(b))"

Process-related error assertions:

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, a.Start() == nil) -> assert.NilError(t, a.Start())"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, a.Start() == nil) -> assert.Check(t, a.Start())"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, a.Kill() == nil) -> assert.NilError(t, a.Kill())"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, a.Kill() == nil) -> assert.Check(t, a.Kill())"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, a.Signal(b) == nil) -> assert.NilError(t, a.Signal(b))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, a.Signal(b) == nil) -> assert.Check(t, a.Signal(b))"

waitInspect:

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, waitInspect(a, b, c, d) == nil) -> assert.NilError(t, waitInspect(a, b, c, d))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, waitInspect(a, b, c, d) == nil) -> assert.Check(t, waitInspect(a, b, c, d))"

File closing error assertions:

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, a.Close() == nil) -> assert.NilError(t, a.Close())"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, a.Close() == nil) -> assert.Check(t, a.Close())"

mount.MakeRShared:

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, mount.MakeRShared(a) == nil) -> assert.NilError(t, mount.MakeRShared(a))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, mount.MakeRShared(a) == nil) -> assert.Check(t, mount.MakeRShared(a))"

daemon.SwarmLeave:

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, d.SwarmLeave(a, b, c) == nil) -> assert.NilError(t, d.SwarmLeave(a, b, c))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, d.SwarmLeave(a, b, c) == nil) -> assert.Check(t, d.SwarmLeave(a, b, c))"

os.MkdirAll:

  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Assert(t, os.MkdirAll(a, b) == nil) -> assert.NilError(t, os.MkdirAll(a, b))"
  find . -type f -name "*_test.go" | \
    xargs gofmt -w -r "assert.Check(t, os.MkdirAll(a, b) == nil) -> assert.Check(t, os.MkdirAll(a, b))"

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

integration-cli/docker_cli_network_unix_test.go

@@ -991,7 +991,7 @@ func (s *DockerNetworkSuite) TestDockerNetworkDriverUngracefulRestart(c *testing
 	assert.NilError(c, err)
 
 	// Kill daemon and restart
-	assert.Assert(c, s.d.Kill() == nil)
+	assert.NilError(c, s.d.Kill())
 
 	server.Close()
 
@@ -1106,7 +1106,7 @@ func (s *DockerNetworkSuite) TestDockerNetworkMultipleNetworksUngracefulDaemonRe
 	verifyContainerIsConnectedToNetworks(c, s.d, cName, nwList)
 
 	// Kill daemon and restart
-	assert.Assert(c, s.d.Kill() == nil)
+	assert.NilError(c, s.d.Kill())
 	s.d.Restart(c)
 
 	// Restart container
@@ -1139,7 +1139,7 @@ func (s *DockerNetworkSuite) TestDockerNetworkHostModeUngracefulDaemonRestart(c
 	}
 
 	// Kill daemon ungracefully and restart
-	assert.Assert(c, s.d.Kill() == nil)
+	assert.NilError(c, s.d.Kill())
 	s.d.Restart(c)
 
 	// make sure all the containers are up and running