Windows API for rust giving "Interface not registered" error when constructing PrintManager - windows

I am attempting to use the windows rust crate API to print a jpeg in rust
first I import the PrintManager using use windows::Graphics::Printing::PrintManager;
then define the main function
fn main() {
and attempt to create a PrintManager using the GetForCurrentView method
let print_manager = PrintManager::GetForCurrentView().unwrap();
however when I run it I get the following error
called `Result::unwrap()` on an `Err` value: Error { code: HRESULT(0x80040155), message: "Interface not registered" }
Minimally reproducible example
version = "0.44.0"
features = [
Main Program
use windows::Graphics::Printing::PrintManager;
fn main() {
let print_manager = PrintManager::IsSupported();
// this is where the error gets thrown
let print_manager = PrintManager::GetForCurrentView().unwrap();
I expect for the function to return a PrintManager struct that I can later use to print a JPEG however it keeps throwing this interface not registered error, I have tried running the program as an administrator with no luck.


GraphQL Nexus Schema (nexusjs) doesn't compile with scalar types

I am trying to follow the documentation on the Nexus-Schema (nexusjs) website for adding scalar types to my GraphQL application.
I have tried adding many of the different implementations to my src/types/Types.ts file using the samples provided in the documentation and the interactive examples. My attempts include:
Without a 3rd party libraries:
const DateScalar = scalarType({
name: 'Date',
asNexusMethod: 'date',
description: 'Date custom scalar type',
parseValue(value) {
return new Date(value)
serialize(value) {
return value.getTime()
parseLiteral(ast) {
if (ast.kind === Kind.INT) {
return new Date(ast.value)
return null
With graphql-iso-date 3rd party library:
import { GraphQLDate } from 'graphql-iso-date'
export const DateTime = GraphQLDate
With graphql-scalars 3rd party library (as shown in the ghost example):
export const GQLDate = decorateType(GraphQLDate, {
rootTyping: 'Date',
asNexusMethod: 'date',
I am using this new scalar type in an object definition like the following:
const SomeObject = objectType({
name: 'SomeObject',
definition(t) {'createdAt') // is supposed to be available because of `asNexusMethod`
In all cases, these types are exported from the types file and imported into the makeSchema's types property.
import * as types from './types/Types'
console.log("Found types", types)
export const apollo = new ApolloServer({
schema: makeSchema({
The console.log statement above does show that consts declared in the types file are in scope:
Found types {
GQLDate: Date,
If I run the app in development mode, everything boots up and runs fine.
ts-node-dev --transpile-only ./src/app.ts
However, I encounter errors whenever I try to compile the app to deploy to a server
ts-node ./src/app.ts && tsc
Note: This error occurs occurs running just ts-node ./src/app.ts before it gets to tsc
The errors that shown during the build process are the following:
return new TSError(diagnosticText, diagnosticCodes)
TSError: тип Unable to compile TypeScript:
src/types/SomeObject.ts:11:7 - error TS2339: Property 'date' does not exist on type 'ObjectDefinitionBlock<"SomeObject">'.
Does anyone have any ideas on either:
a) How can I work around this error? While long-term solutions are ideal, temporary solutions would also be appreciated.
b) Any steps I could follow to debug this error? Or ideas on how get additional information to assist with debugging?
Any assistance would be very much welcomed. Thanks!
The issue seems to be resolved when --transpile-only flag is added to the nexus:reflect command.
This means the reflection command gets updated to:
ts-node --transpile-only ./src/app.ts
and the build comand gets updated to:
env-cmd -f ./config/.env ts-node --transpile-only ./src/app.ts --nexusTypegen && tsc
A github issue has also been created which can be reviewed here:

Rust doesn't accept input from stdin from native messaging - firefox

I am making a native messaging application, with the web API, from firefox. The extension is supposed to call an application that parses stdin and then calls my other rust app, based on some of the data it parsed, but for no apparent reason, the rust app doesn't accept input from firefox (it works when I do it manually).
This is the code of the extension:
On a click on the browser action, send the app a message.
browser.browserAction.onClicked.addListener(() => {
console.log("Sending: ping");
var sending = browser.runtime.sendNativeMessage(
sending.then(onResponse, onError);
function onResponse(response) {
console.log("Received " + response);
function onError(error) {
console.log(`Error: ${error}`);
and this the code of the rust app:
use std::fs;
use std::io;
use std::io::prelude::*;
fn main() {
let stdin = io::stdin();
for line in stdin.lock().lines() {
let mut file = fs::File::create("/home/user/filename.txt").unwrap();
if line.unwrap() == "ping" {
The weird thing is, that the text file in my home dir first appears, when I close firefox, not when the app gets started. And it also doen't have the text TEST.
Thanks for any help!
I managed to make my own solution, taking a bit from this crate.
Quick note: "If you want to skip all of the code and immeditly want to start coding from a template repo, scoll to the bottom of this solution, and you should be able to find more info there."
The code, which reads the input, and then returns it, is the following:
pub fn read_input<R: Read>(mut input: R) -> io::Result<serde_json::Value> {
let length = input.read_u32::<NativeEndian>().unwrap();
let mut buffer = vec![0; length as usize];
input.read_exact(&mut buffer)?;
let json_val: serde_json::Value = serde_json::from_slice(&buffer).unwrap();
What the code does, is read the input, which is being passed as a parameter to the function, and then it reads it parses it in a json var and returns the sucess/err value of it.
That code is being used in the file like this:
let json_val = match lib::read_input(io::stdin()) {
Err(why) => panic!("{}", why.to_string()),
Ok(json_val) => json_val,
Here the input is being passed as a parameter to the read_input function.
And to send the code i used the following function:
pub fn write_output<W: Write>(mut output: W, value: &serde_json::Value) -> io::Result<()> {
let msg = serde_json::to_string(value)?;
let len = msg.len();
// Chrome won't accept a message larger than 1MB
if len > 1024 * 1024 {
panic!("Message was too large", length: {}, len)
output.write_u32::<NativeEndian>(len as u32)?;
Which gets the stdout and the message passed as parameters. The function then writes the message to the output (normally stdout, could also be a file for debugging purposes).
The code which calls the function write_output is the following:
let response = serde_json::json!({ "msg": "pong" });
match lib::write_output(io::stdout(), &response) {
Err(why) => panic!("{}", why.to_string()),
Ok(_) => (),
The project uses these dependencies, so make sure to add them to Cargo.toml
"byteorder" = "*"
"serde_json" = "*"
The imports for the file are:
mod lib;
use std::io;
and for the file, in which both functions reside:
extern crate serde_json;
use byteorder::{NativeEndian, ReadBytesExt, WriteBytesExt};
use std::error::Error;
use std::fs;
use std::io;
use std::io::{Read, Write};
I also created a git template repo, so that you can start really quick, you can find it here.

How to debug an import binding name that is not found

I have a NativeScript application that I'm trying to add iBeacon support to using the iBeacon plugin. The application builds successfully and is synced to my phone (I'm using SideKick). When the app runs, it has a fatal javascript exception. The javascript error is reported at:
file:///app/tns_modules/tns-core-modules/ui/builder/builder.js:244:56: JS ERROR Error: Building UI from XML. #file:///app/app-root.xml:18:9
That line is where the page that attempts to access the iBeacon code is defined:
<Frame defaultPage="views/search/search-page"></Frame>
and the specific error is:
Importing binding name 'BeaconLocationOptions' is not found.
I'm assuming this occurs as part of the following import statement:
import {NativescriptIbeacon, BeaconCallback, BeaconLocationOptions, BeaconLocationOptionsIOSAuthType, BeaconLocationOptionsAndroidAuthType, BeaconRegion, Beacon } from 'nativescript-ibeacon';
The above import statement is what is documented as part of the iBeacon documentation.
There is a nativescript-ibeacon directory under node_modules in my project. The specific ios file seems to be there:
I'm not sure if it is a problem in my code or a problem with configuration - maybe something missing that stops the ibeacon files from being deployed properly to the device.
My code is in javascript, but I have installed the typescript plugin. It looks like this iBeacon plugin assumes the app is written in typescript.
I'm looking for help in determining what to try next.
FYI...I've tried pulling the source files out of the node_modules and incorporating them directly into my project. After resolving many issues with this approach, I eventually hit the same wall - a problem importing the code when running on the device.
Below is the code that is using the iBeacon plugin:
const observableModule = require("tns-core-modules/data/observable");
import {NativescriptIbeacon, BeaconCallback, BeaconLocationOptions, BeaconLocationOptionsIOSAuthType, BeaconLocationOptionsAndroidAuthType, BeaconRegion, Beacon } from 'nativescript-ibeacon';
function SearchViewModel() {
let callback = {
onBeaconManagerReady() {
// start ranging and/or monitoring only when the beacon manager is ready
didRangeBeaconsInRegion: function(region, beacons) {
didFailRangingBeaconsInRegion: function(region, errorCode, errorDescription) {
let options = {
iOSAuthorisationType: BeaconLocationOptionsIOSAuthType.Always,
androidAuthorisationType: BeaconLocationOptionsAndroidAuthType.Coarse,
androidAuthorisationDescription: "Location permission needed"
let nativescriptIbeacon = new NativescriptIbeacon(callback, options);
let region = new BeaconRegion("HelloID", "2f234454-cf6d-4a0f-adf2-f4911ba9ffa6");
const viewModel = observableModule.fromObject({
"beaconData": "not set yet",
"onTapStart": function() {
this.set("beaconData", "started");
console.log("tapped start");
if (!nativescriptIbeacon.isAuthorised()) {
console.log("NOT Authorised");
.then(() => {
console.log("Authorised by the user");
}, (e) => {
console.log("Authorisation denied by the user");
} else {
console.log("Already authorised");
"onTapStop": function() {
this.set("beaconData", "stopped");
console.log("tapped stop");
return viewModel;
module.exports = SearchViewModel;
I have created a playground for you here.
If you look into example, I am importing NativescriptIbeacon from the main folder and rest from the common folder.
P.S. This plugin has dependency on nativescript-permission
import { NativescriptIbeacon } from '../nativescript-ibeacon';
import {
BeaconRegion, Beacon, BeaconCallback,
BeaconLocationOptions, BeaconLocationOptionsIOSAuthType, BeaconLocationOptionsAndroidAuthType
} from "../nativescript-ibeacon/nativescript-ibeacon.common";
This answer solved my problem along with another modification. After splitting the import up I still had the same error. Then I read the following page about modules:
Based on this statement:
If the module identifier passed to require(moduleName) does not begin
with '/', '../', or './', then NativeScript will lookup the module
within the tns_modules folder
I assumed that maybe only require does the proper lookup into tns_modules.
I refactored the import to use require instead, and that worked. My changes are below. There may be a more efficient way to do this, but it worked for me.
const nsb = require("nativescript-ibeacon/nativescript-ibeacon.js");
const nsbc = require("nativescript-ibeacon/nativescript-ibeacon.common.js");
const NativescriptIbeacon = nsb.NativescriptIbeacon;
const BeaconCallback = nsbc.BeaconCallback;
const BeaconLocationOptions = nsbc.BeaconLocationOptions;
const BeaconLocationOptionsIOSAuthType = nsbc.BeaconLocationOptionsIOSAuthType;
const BeaconLocationOptionsAndroidAuthType = nsbc.BeaconLocationOptionsAndroidAuthType
const BeaconRegion = nsbc.BeaconRegion;
const Beacon = nsbc.Beacon;

Protobuf (gRPC) Code Generator for Go Creating Invalid Code

Everything works when I have my proto file defining a service with a streaming response. However when I return a single value, then the generated code is invalid!
Proto File:
syntax = "proto3";
package analyticsServicesGlobal;
option go_package = "generated/analyticsServices";
service HealthCheck {
rpc Health (HealthCheckParam) returns (HealthCheckPayload) {}
message HealthCheckPayload {
string message = 1;
message HealthCheckParam {
string response = 1;
The code generation completes without issue : protoc --go_out=plugins=grpc:$GOPATH/src/gauss minimal.proto
The ide and command line compilation return this error in the generated Go code though:
./minimal.pb.go:130: cannot use handler (type func("gauss/vendor/".Context, interface {}) (interface {}, error)) as type grpc.UnaryHandler in argument to interceptor
./minimal.pb.go:139: cannot use _HealthCheck_Health_Handler (type func(interface {}, "gauss/vendor/".Context, func(interface {}) error, grpc.UnaryServerInterceptor) (interface {}, error)) as type grpc.methodHandler in field value
This issue shows up for any service where a non-stream response is returned. I have create this minimal proto file to demonstrate, but every similar service definition has the same issue.
I am on OSX using Go version 1.8.1, protoc version 3.3.0, and the latest protoc plugin for Go go get -u{proto,protoc-gen-go}
I'm sure I'm doing something wrong given the lack of reports on this issue - but I don't see what. Any suggestions are appreciated!

Unable to test a Golang CLI tool's output

I have a cli tool written in Go which produces the following output:
Command: config get
Env: int
Component: foo-component
Unable to find any configuration within Cosmos ( for foo-component.
I would like to verify this output within a test.
The test I have written (and doesn't pass) is as follows:
package command
import (
type FakeCliContext struct{}
func (s FakeCliContext) String(name string) string {
return "foobar"
func ExampleInvalidComponentReturnsError() {
fakeBaseURL := ""
fakeCliContext := &FakeCliContext{}
fakeFetchFlag := func(foo.CliContext) (map[string]string, error) {
return map[string]string{
"env": "int",
"component": "foo-component",
}, nil
GetConfig(*fakeCliContext, fakeFetchFlag, fakeBaseURL)
// Output:
// Command: config get
// Env: int
// Component: foo-component
// Unable to find any configuration within Cosmos ( for foo-component.
The majority of the code is creating fake objects that I'm injecting into my function call GetConfig.
Effectively there is no return value from GetConfig only a side effect of text being printed to stdout.
So I'm using the Example<NameOfTest> format to try and verify the output.
But all I just back when I run go test -v is:
=== RUN ExampleInvalidComponentReturnsError
exit status 1
FAIL 0.418s
Does anyone know what I might be missing?
I've found that if I add an additional test after the 'Example' one above, for example called Test<NameOfTest> (but consistenting of effectively the same code), then this will actually display the function's output into my stdout when running the test:
func TestInvalidComponentReturnsError(t *testing.T) {
fakeBaseURL := ""
fakeCliContext := &FakeCliContext{}
fakeFetchFlag := func(utils.CliContext) (map[string]string, error) {
return map[string]string{
"env": "int",
"component": "foo-component",
}, nil
GetConfig(*fakeCliContext, fakeFetchFlag, fakeBaseURL)
The above example test will now show the following output when executing go test -v:
=== RUN TestInvalidComponentReturnsError
Command: config get
Env: int
Component: foo-component
Unable to find any configuration within Cosmos ( for foo-component.
exit status 1
FAIL 0.938s
OK so the solution to this problem was part architecture and part removal/refactor of code.
I extracted the private functions from the cli command package so they became public functions in a separate function
I refactored the code so that all dependencies were injected, this then allowed me to mock these objects and verify the the expected methods were called
Now the private functions are in a package and made public, I'm able to test those things specifically, outside of the cli context
Finally, I removed the use of os.Exit as that was a nightmare to deal with and wasn't really necessary