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Allowed PythonShell to work with unset std streams #190 #191

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Merged
merged 1 commit into from
Aug 2, 2019
Merged

Allowed PythonShell to work with unset std streams #190 #191

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47 changes: 29 additions & 18 deletions index.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -138,29 +138,37 @@ export class PythonShell extends EventEmitter{

['stdout', 'stdin', 'stderr'].forEach(function (name) {
self[name] = self.childProcess[name];
self.parser && self[name].setEncoding(options.encoding || 'utf8');
self.parser && self[name] && self[name].setEncoding(options.encoding || 'utf8');
});

// parse incoming data on stdout
if (this.parser) {
if (this.parser && this.stdout) {
this.stdout.on('data', this.receive.bind(this));
}

// listen to stderr and emit errors for incoming data
this.stderr.on('data', function (data) {
errorData += ''+data;
self.receiveStderr(data);
});
if (this.stderr) {
this.stderr.on('data', function (data) {
errorData += ''+data;
self.receiveStderr(data);
});

this.stderr.on('end', function(){
self.stderrHasEnded = true
terminateIfNeeded();
})
this.stderr.on('end', function(){
self.stderrHasEnded = true;
terminateIfNeeded();
});
} else {
self.stderrHasEnded = true;
}

this.stdout.on('end', function(){
self.stdoutHasEnded = true
terminateIfNeeded();
})
if (this.stdout) {
this.stdout.on('end', function(){
self.stdoutHasEnded = true;
terminateIfNeeded();
});
} else {
self.stdoutHasEnded = true;
}

this.childProcess.on('exit', function (code,signal) {
self.exitCode = code;
Expand Down Expand Up @@ -339,6 +347,7 @@ export class PythonShell extends EventEmitter{
* @returns {PythonShell} The same instance for chaining calls
*/
send(message:string|Object) {
if (!this.stdin) throw new Error("stdin not open for writting");
let data = this.formatter ? this.formatter(message) : message;
if (this.mode !== 'binary') data += newline;
this.stdin.write(data);
Expand All @@ -352,7 +361,7 @@ export class PythonShell extends EventEmitter{
* @param {string|Buffer} data The data to parse into messages
*/
receive(data:string|Buffer) {
return this.recieveInternal(data, 'message');
return this.receiveInternal(data, 'message');
};

/**
Expand All @@ -362,10 +371,10 @@ export class PythonShell extends EventEmitter{
* @param {string|Buffer} data The data to parse into messages
*/
receiveStderr(data:string|Buffer) {
return this.recieveInternal(data, 'stderr');
return this.receiveInternal(data, 'stderr');
};

private recieveInternal(data:string|Buffer, emitType:'message'|'stderr'){
private receiveInternal(data:string|Buffer, emitType:'message'|'stderr'){
let self = this;
let parts = (''+data).split(new RegExp(newline,'g'));

Expand Down Expand Up @@ -394,7 +403,9 @@ export class PythonShell extends EventEmitter{
* @returns {PythonShell} The same instance for chaining calls
*/
end(callback:(err:PythonShellError, exitCode:number,exitSignal:string)=>any) {
this.childProcess.stdin.end();
if (this.childProcess.stdin) {
this.childProcess.stdin.end();
}
this._endCallback = callback;
return this;
};
Expand Down
16 changes: 16 additions & 0 deletions test/test-python-shell.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -225,6 +225,22 @@ describe('PythonShell', function () {
scriptPath: pythonFolder
};
})

it('should run PythonShell normally without access to std streams', function (done) {
var pyshell = PythonShell.run('exit-code.py', {
// 3 different ways of assigning values to the std streams in child_process.spawn()
// * ignore - pipe to /dev/null
// * inherit - inherit fd from parent process;
// * process.stderr - pass output directly to that stream.
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@Almenon Almenon Aug 2, 2019

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I read up on https://nodejs.org/api/child_process.html#child_process_options_stdio, interesting stuff, thanks!

stdio: ['ignore', 'inherit', process.stderr],
args: ["0"]
}, done);

should(pyshell.stdin).be.eql(null);
should(pyshell.stdout).be.eql(null);
should(pyshell.stderr).be.eql(null);
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@Almenon Almenon Aug 2, 2019

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Why is stdout and stderr null? Because these both inherit the parent's stdout / stderr shouldn't they have a value?

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@joaoe joaoe Aug 2, 2019 •
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They should be null. The underlying code does a file descriptor dup() so the child process just inherits the file descriptors directly and then all output goes to /dev/tty (for instance, if you are working in a terminal) bypassing any streams in memory in the local process (in the case of using inherit).

should.throws(() => {pyshell.send("asd")});
});
});

describe('.send(message)', function () {
Expand Down