Alayna  Rippin

Alayna Rippin

1602321072

Cool Stuff With Go’s AST Package

This is the second part of the walkthrough “Cool Stuff with Go’s AST Package.” If you have not yet had the opportunity to review the first article, I recommend starting there to become acquainted with abstract syntax trees, the Go package itself, and the facilities provided by the package for traversing Go’s AST.

What we Will be Covering

In the first article we introduced NATS and how it can be used to create a microservice that publishes regular heartbeats on a message topic. One side-effect of implementing a microservices architecture based on NATS is that all of the various topics, subscribers, publishers, and message types can become blurred, and it is easy to lose track of them.

We discussed the idea of creating a self-documenting microservice using the source code itself. The program will operate similar to other tools that produce OpenAPI specification documents from APIs (Swagger) and will be driven by the source code, without having to document anything externally to the system.

In the first article we covered extracting out the topic name from the publish method, as well as some basic traversal techniques and type switching based on the different nodes found in the abstract syntax tree. Now that we have a topic, we can move onto providing some additional context around the topic, as well as signaling the type of message the topic is producing. By the end of this article we will have additional functionality that will allow us to extract value from the following structured comment:

//Description: The heartbeat topic will publish a message at regular
//    intervals to signal system uptime
// Publishes: HeartBeatMsg
ec.Publish("heartbeat", msg)

In the comment preceding the function call, we specify a description as well as the message type that will be published on the “heartbeat” topic. Let’s dive into how this will work.

#golang #coding #programming #software-engineering #development

What is GEEK

Buddha Community

Cool Stuff With Go’s AST Package
Mike  Kozey

Mike Kozey

1656151740

Test_cov_console: Flutter Console Coverage Test

Flutter Console Coverage Test

This small dart tools is used to generate Flutter Coverage Test report to console

How to install

Add a line like this to your package's pubspec.yaml (and run an implicit flutter pub get):

dev_dependencies:
  test_cov_console: ^0.2.2

How to run

run the following command to make sure all flutter library is up-to-date

flutter pub get
Running "flutter pub get" in coverage...                            0.5s

run the following command to generate lcov.info on coverage directory

flutter test --coverage
00:02 +1: All tests passed!

run the tool to generate report from lcov.info

flutter pub run test_cov_console
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
 print_cov_constants.dart                    |    0.00 |    0.00 |    0.00 |    no unit testing|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

Optional parameter

If not given a FILE, "coverage/lcov.info" will be used.
-f, --file=<FILE>                      The target lcov.info file to be reported
-e, --exclude=<STRING1,STRING2,...>    A list of contains string for files without unit testing
                                       to be excluded from report
-l, --line                             It will print Lines & Uncovered Lines only
                                       Branch & Functions coverage percentage will not be printed
-i, --ignore                           It will not print any file without unit testing
-m, --multi                            Report from multiple lcov.info files
-c, --csv                              Output to CSV file
-o, --output=<CSV-FILE>                Full path of output CSV file
                                       If not given, "coverage/test_cov_console.csv" will be used
-t, --total                            Print only the total coverage
                                       Note: it will ignore all other option (if any), except -m
-p, --pass=<MINIMUM>                   Print only the whether total coverage is passed MINIMUM value or not
                                       If the value >= MINIMUM, it will print PASSED, otherwise FAILED
                                       Note: it will ignore all other option (if any), except -m
-h, --help                             Show this help

example run the tool with parameters

flutter pub run test_cov_console --file=coverage/lcov.info --exclude=_constants,_mock
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

report for multiple lcov.info files (-m, --multi)

It support to run for multiple lcov.info files with the followings directory structures:
1. No root module
<root>/<module_a>
<root>/<module_a>/coverage/lcov.info
<root>/<module_a>/lib/src
<root>/<module_b>
<root>/<module_b>/coverage/lcov.info
<root>/<module_b>/lib/src
...
2. With root module
<root>/coverage/lcov.info
<root>/lib/src
<root>/<module_a>
<root>/<module_a>/coverage/lcov.info
<root>/<module_a>/lib/src
<root>/<module_b>
<root>/<module_b>/coverage/lcov.info
<root>/<module_b>/lib/src
...
You must run test_cov_console on <root> dir, and the report would be grouped by module, here is
the sample output for directory structure 'with root module':
flutter pub run test_cov_console --file=coverage/lcov.info --exclude=_constants,_mock --multi
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|
---------------------------------------------|---------|---------|---------|-------------------|
File - module_a -                            |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|
---------------------------------------------|---------|---------|---------|-------------------|
File - module_b -                            |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

Output to CSV file (-c, --csv, -o, --output)

flutter pub run test_cov_console -c --output=coverage/test_coverage.csv

#### sample CSV output file:
File,% Branch,% Funcs,% Lines,Uncovered Line #s
lib/,,,,
test_cov_console.dart,0.00,0.00,0.00,no unit testing
lib/src/,,,,
parser.dart,100.00,100.00,97.22,"97"
parser_constants.dart,100.00,100.00,100.00,""
print_cov.dart,100.00,100.00,82.91,"29,49,51,52,171,174,177,180,183,184,185,186,187,188,279,324,325,387,388,389,390,391,392,393,394,395,398"
print_cov_constants.dart,0.00,0.00,0.00,no unit testing
All files with unit testing,100.00,100.00,86.07,""

Installing

Use this package as an executable

Install it

You can install the package from the command line:

dart pub global activate test_cov_console

Use it

The package has the following executables:

$ test_cov_console

Use this package as a library

Depend on it

Run this command:

With Dart:

 $ dart pub add test_cov_console

With Flutter:

 $ flutter pub add test_cov_console

This will add a line like this to your package's pubspec.yaml (and run an implicit dart pub get):

dependencies:
  test_cov_console: ^0.2.2

Alternatively, your editor might support dart pub get or flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:test_cov_console/test_cov_console.dart';

example/lib/main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
        // This makes the visual density adapt to the platform that you run
        // the app on. For desktop platforms, the controls will be smaller and
        // closer together (more dense) than on mobile platforms.
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

Author: DigitalKatalis
Source Code: https://github.com/DigitalKatalis/test_cov_console 
License: BSD-3-Clause license

#flutter #dart #test 

Fannie  Zemlak

Fannie Zemlak

1599854400

What's new in the go 1.15

Go announced Go 1.15 version on 11 Aug 2020. Highlighted updates and features include Substantial improvements to the Go linker, Improved allocation for small objects at high core counts, X.509 CommonName deprecation, GOPROXY supports skipping proxies that return errors, New embedded tzdata package, Several Core Library improvements and more.

As Go promise for maintaining backward compatibility. After upgrading to the latest Go 1.15 version, almost all existing Golang applications or programs continue to compile and run as older Golang version.

#go #golang #go 1.15 #go features #go improvement #go package #go new features

Send Email in Golang using Go Mail Package | Emails in Go

Send an email with Golang using a popular package Gomail.

Gomail is a simple and efficient package to send emails. It is well tested and documented.
Gomail can only send emails using an SMTP server. But the API is flexible and it is easy to implement other methods for sending emails using a local Postfix, an API, etc.
Install Gomail: go get gopkg.in/gomail.v2

#golang #Gomail #emailGolang #GolangEMail

#golang #go mail package #go

Alayna  Rippin

Alayna Rippin

1602321072

Cool Stuff With Go’s AST Package

This is the second part of the walkthrough “Cool Stuff with Go’s AST Package.” If you have not yet had the opportunity to review the first article, I recommend starting there to become acquainted with abstract syntax trees, the Go package itself, and the facilities provided by the package for traversing Go’s AST.

What we Will be Covering

In the first article we introduced NATS and how it can be used to create a microservice that publishes regular heartbeats on a message topic. One side-effect of implementing a microservices architecture based on NATS is that all of the various topics, subscribers, publishers, and message types can become blurred, and it is easy to lose track of them.

We discussed the idea of creating a self-documenting microservice using the source code itself. The program will operate similar to other tools that produce OpenAPI specification documents from APIs (Swagger) and will be driven by the source code, without having to document anything externally to the system.

In the first article we covered extracting out the topic name from the publish method, as well as some basic traversal techniques and type switching based on the different nodes found in the abstract syntax tree. Now that we have a topic, we can move onto providing some additional context around the topic, as well as signaling the type of message the topic is producing. By the end of this article we will have additional functionality that will allow us to extract value from the following structured comment:

//Description: The heartbeat topic will publish a message at regular
//    intervals to signal system uptime
// Publishes: HeartBeatMsg
ec.Publish("heartbeat", msg)

In the comment preceding the function call, we specify a description as well as the message type that will be published on the “heartbeat” topic. Let’s dive into how this will work.

#golang #coding #programming #software-engineering #development

Rust  Language

Rust Language

1640144506

Strings - The Rust Programming Language

Rust For Beginners Tutorial - Strings

In this video we're taking a look at the String, &String and &str types in Rust!

Exercise solutions: https://github.com/PascalPrecht/rustlings/commits/solutions 

---
0:00 Intro
0:09 Exercise 1
4:47 Exercise 2
10:38 Outro


Strings

There are two types of strings in Rust: String and &str.

A String is stored as a vector of bytes (Vec<u8>), but guaranteed to always be a valid UTF-8 sequence. String is heap allocated, growable and not null terminated.

&str is a slice (&[u8]) that always points to a valid UTF-8 sequence, and can be used to view into a String, just like &[T] is a view into Vec<T>.

fn main() {
    // (all the type annotations are superfluous)
    // A reference to a string allocated in read only memory
    let pangram: &'static str = "the quick brown fox jumps over the lazy dog";
    println!("Pangram: {}", pangram);

    // Iterate over words in reverse, no new string is allocated
    println!("Words in reverse");
    for word in pangram.split_whitespace().rev() {
        println!("> {}", word);
    }

    // Copy chars into a vector, sort and remove duplicates
    let mut chars: Vec<char> = pangram.chars().collect();
    chars.sort();
    chars.dedup();

    // Create an empty and growable `String`
    let mut string = String::new();
    for c in chars {
        // Insert a char at the end of string
        string.push(c);
        // Insert a string at the end of string
        string.push_str(", ");
    }

    // The trimmed string is a slice to the original string, hence no new
    // allocation is performed
    let chars_to_trim: &[char] = &[' ', ','];
    let trimmed_str: &str = string.trim_matches(chars_to_trim);
    println!("Used characters: {}", trimmed_str);

    // Heap allocate a string
    let alice = String::from("I like dogs");
    // Allocate new memory and store the modified string there
    let bob: String = alice.replace("dog", "cat");

    println!("Alice says: {}", alice);
    println!("Bob says: {}", bob);
}

More str/String methods can be found under the std::str and std::string modules

Literals and escapes

There are multiple ways to write string literals with special characters in them. All result in a similar &str so it's best to use the form that is the most convenient to write. Similarly there are multiple ways to write byte string literals, which all result in &[u8; N].

Generally special characters are escaped with a backslash character: \. This way you can add any character to your string, even unprintable ones and ones that you don't know how to type. If you want a literal backslash, escape it with another one: \\

String or character literal delimiters occuring within a literal must be escaped: "\"", '\''.

fn main() {
    // You can use escapes to write bytes by their hexadecimal values...
    let byte_escape = "I'm writing \x52\x75\x73\x74!";
    println!("What are you doing\x3F (\\x3F means ?) {}", byte_escape);

    // ...or Unicode code points.
    let unicode_codepoint = "\u{211D}";
    let character_name = "\"DOUBLE-STRUCK CAPITAL R\"";

    println!("Unicode character {} (U+211D) is called {}",
                unicode_codepoint, character_name );


    let long_string = "String literals
                        can span multiple lines.
                        The linebreak and indentation here ->\
                        <- can be escaped too!";
    println!("{}", long_string);
}

Sometimes there are just too many characters that need to be escaped or it's just much more convenient to write a string out as-is. This is where raw string literals come into play.

fn main() {
    let raw_str = r"Escapes don't work here: \x3F \u{211D}";
    println!("{}", raw_str);

    // If you need quotes in a raw string, add a pair of #s
    let quotes = r#"And then I said: "There is no escape!""#;
    println!("{}", quotes);

    // If you need "# in your string, just use more #s in the delimiter.
    // There is no limit for the number of #s you can use.
    let longer_delimiter = r###"A string with "# in it. And even "##!"###;
    println!("{}", longer_delimiter);
}

Want a string that's not UTF-8? (Remember, str and String must be valid UTF-8). Or maybe you want an array of bytes that's mostly text? Byte strings to the rescue!

use std::str;

fn main() {
    // Note that this is not actually a `&str`
    let bytestring: &[u8; 21] = b"this is a byte string";

    // Byte arrays don't have the `Display` trait, so printing them is a bit limited
    println!("A byte string: {:?}", bytestring);

    // Byte strings can have byte escapes...
    let escaped = b"\x52\x75\x73\x74 as bytes";
    // ...but no unicode escapes
    // let escaped = b"\u{211D} is not allowed";
    println!("Some escaped bytes: {:?}", escaped);


    // Raw byte strings work just like raw strings
    let raw_bytestring = br"\u{211D} is not escaped here";
    println!("{:?}", raw_bytestring);

    // Converting a byte array to `str` can fail
    if let Ok(my_str) = str::from_utf8(raw_bytestring) {
        println!("And the same as text: '{}'", my_str);
    }

    let _quotes = br#"You can also use "fancier" formatting, \
                    like with normal raw strings"#;

    // Byte strings don't have to be UTF-8
    let shift_jis = b"\x82\xe6\x82\xa8\x82\xb1\x82\xbb"; // "ようこそ" in SHIFT-JIS

    // But then they can't always be converted to `str`
    match str::from_utf8(shift_jis) {
        Ok(my_str) => println!("Conversion successful: '{}'", my_str),
        Err(e) => println!("Conversion failed: {:?}", e),
    };
}

For conversions between character encodings check out the encoding crate.

A more detailed listing of the ways to write string literals and escape characters is given in the 'Tokens' chapter of the Rust Reference.

#rust #programming #developer