1620316020

Writing Custom Linter in Go

Writing linters is simple. I was surprised how it’s easy to write a Go linter. Today, we’ll write a linter that will calculate the cyclomatic complexity of the Go code.

What is cyclomatic complexity?

Cyclomatic complexity is a software metric used to indicate the complexity of a program. ref

The idea is simple — every time we find any control flow statements we increase the complexity by one. I know I oversimplified it a bit but I don’t want to overwhelm you with unnecessary details.

There are a few steps we should follow to write our custom linter. Firstly, we can create a test that will check if our linter works or not. Let’s put him into pkg/analyzer/analyzer_test.go file.

package analyzer

import (
	"os"
	"path/filepath"
	"testing"

	"golang.org/x/tools/go/analysis/analysistest"
)

func TestAll(t *testing.T) {
	wd, err := os.Getwd()
	if err != nil {
		t.Fatalf("Failed to get wd: %s", err)
	}

	testdata := filepath.Join(filepath.Dir(filepath.Dir(wd)), "testdata")
	analysistest.Run(t, testdata, NewAnalyzer(), "complexity")
}

The analysistest.Run() function is a helper that simplifies testing linters. What it does is running our linter on package complexity in testate folder. We use NewAnalyzer() function that will return instance of our analyzer. Let’s add it to pkg/analyzer/analyzer.go.

#go #golang #linter

What is GEEK

Buddha Community

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

Chesley Labadie

1648972740

Generis: Versatile Go Code Generator

Generis

Versatile Go code generator.

Description

Generis is a lightweight code preprocessor adding the following features to the Go language :

Generics.
Free-form macros.
Conditional compilation.
HTML templating.
Allman style conversion.

Sample

package main;

// -- IMPORTS

import (
    "html"
    "io"
    "log"
    "net/http"
    "net/url"
    "strconv"
    );

// -- DEFINITIONS

#define DebugMode
#as true

// ~~

#define HttpPort
#as 8080

// ~~

#define WriteLine( {{text}} )
#as log.Println( {{text}} )

// ~~

#define local {{variable}} : {{type}};
#as var {{variable}} {{type}};

// ~~

#define DeclareStack( {{type}}, {{name}} )
#as
    // -- TYPES

    type {{name}}Stack struct
    {
        ElementArray []{{type}};
    }

    // -- INQUIRIES

    func ( stack * {{name}}Stack ) IsEmpty(
        ) bool
    {
        return len( stack.ElementArray ) == 0;
    }

    // -- OPERATIONS

    func ( stack * {{name}}Stack ) Push(
        element {{type}}
        )
    {
        stack.ElementArray = append( stack.ElementArray, element );
    }

    // ~~

    func ( stack * {{name}}Stack ) Pop(
        ) {{type}}
    {
        local
            element : {{type}};

        element = stack.ElementArray[ len( stack.ElementArray ) - 1 ];

        stack.ElementArray = stack.ElementArray[ : len( stack.ElementArray ) - 1 ];

        return element;
    }
#end

// ~~

#define DeclareStack( {{type}} )
#as DeclareStack( {{type}}, {{type:PascalCase}} )

// -- TYPES

DeclareStack( string )
DeclareStack( int32 )

// -- FUNCTIONS

func HandleRootPage(
    response_writer http.ResponseWriter,
    request * http.Request
    )
{
    local
        boolean : bool;
    local
        natural : uint;
    local
        integer : int;
    local
        real : float64;
    local
        escaped_html_text,
        escaped_url_text,
        text : string;
    local
        integer_stack : Int32Stack;

    boolean = true;
    natural = 10;
    integer = 20;
    real = 30.0;
    text = "text";
    escaped_url_text = "&escaped text?";
    escaped_html_text = "<escaped text/>";

    integer_stack.Push( 10 );
    integer_stack.Push( 20 );
    integer_stack.Push( 30 );

    #write response_writer
        <!DOCTYPE html>
        <html lang="en">
            <head>
                <meta charset="utf-8">
                <title><%= request.URL.Path %></title>
            </head>
            <body>
                <% if ( boolean ) { %>
                    <%= "URL : " + request.URL.Path %>
                    <br/>
                    <%@ natural %>
                    <%# integer %>
                    <%& real %>
                    <br/>
                    <%~ text %>
                    <%^ escaped_url_text %>
                    <%= escaped_html_text %>
                    <%= "<%% ignored %%>" %>
                    <%% ignored %%>
                <% } %>
                <br/>
                Stack :
                <br/>
                <% for !integer_stack.IsEmpty() { %>
                    <%# integer_stack.Pop() %>
                <% } %>
            </body>
        </html>
    #end
}

// ~~

func main()
{
    http.HandleFunc( "/", HandleRootPage );

    #if DebugMode
        WriteLine( "Listening on http://localhost:HttpPort" );
    #end

    log.Fatal(
        http.ListenAndServe( ":HttpPort", nil )
        );
}

Syntax

#define directive

Constants and generic code can be defined with the following syntax :

#define old code
#as new code

#define old code
#as
    new
    code
#end

#define
    old
    code
#as new code

#define
    old
    code
#as
    new
    code
#end

#define parameter

The #define directive can contain one or several parameters :

{{variable name}} : hierarchical code (with properly matching brackets and parentheses)
{{variable name#}} : statement code (hierarchical code without semicolon)
{{variable name$}} : plain code
{{variable name:boolean expression}} : conditional hierarchical code
{{variable name#:boolean expression}} : conditional statement code
{{variable name$:boolean expression}} : conditional plain code

They can have a boolean expression to require they match specific conditions :

HasText text
HasPrefix prefix
HasSuffix suffix
HasIdentifier text
false
true
!expression
expression && expression
expression || expression
( expression )

The #define directive must not start or end with a parameter.

#as parameter

The #as directive can use the value of the #define parameters :

{{variable name}}
{{variable name:filter function}}
{{variable name:filter function:filter function:...}}

Their value can be changed through one or several filter functions :

LowerCase
UpperCase
MinorCase
MajorCase
SnakeCase
PascalCase
CamelCase
RemoveComments
RemoveBlanks
PackStrings
PackIdentifiers
ReplacePrefix old_prefix new_prefix
ReplaceSuffix old_suffix new_suffix
ReplaceText old_text new_text
ReplaceIdentifier old_identifier new_identifier
AddPrefix prefix
AddSuffix suffix
RemovePrefix prefix
RemoveSuffix suffix
RemoveText text
RemoveIdentifier identifier

#if directive

Conditional code can be defined with the following syntax :

#if boolean expression
    #if boolean expression
        ...
    #else
        ...
    #end
#else
    #if boolean expression
        ...
    #else
        ...
    #end
#end

The boolean expression can use the following operators :

false
true
!expression
expression && expression
expression || expression
( expression )

#write directive

Templated HTML code can be sent to a stream writer using the following syntax :

#write writer expression
    <% code %>
    <%@ natural expression %>
    <%# integer expression %>
    <%& real expression %>
    <%~ text expression %>
    <%= escaped text expression %>
    <%! removed content %>
    <%% ignored tags %%>
#end

Limitations

There is no operator precedence in boolean expressions.
The --join option requires to end the statements with a semicolon.
The #writer directive is only available for the Go language.

Installation

Install the DMD 2 compiler (using the MinGW setup option on Windows).

Build the executable with the following command line :

dmd -m64 generis.d

Command line

generis [options]

Options

--prefix # : set the command prefix
--parse INPUT_FOLDER/ : parse the definitions of the Generis files in the input folder
--process INPUT_FOLDER/ OUTPUT_FOLDER/ : reads the Generis files in the input folder and writes the processed files in the output folder
--trim : trim the HTML templates
--join : join the split statements
--create : create the output folders if needed
--watch : watch the Generis files for modifications
--pause 500 : time to wait before checking the Generis files again
--tabulation 4 : set the tabulation space count
--extension .go : generate files with this extension

Examples

generis --process GS/ GO/

Reads the Generis files in the GS/ folder and writes Go files in the GO/ folder.

generis --process GS/ GO/ --create

Reads the Generis files in the GS/ folder and writes Go files in the GO/ folder, creating the output folders if needed.

generis --process GS/ GO/ --create --watch

Reads the Generis files in the GS/ folder and writes Go files in the GO/ folder, creating the output folders if needed and watching the Generis files for modifications.

generis --process GS/ GO/ --trim --join --create --watch

Reads the Generis files in the GS/ folder and writes Go files in the GO/ folder, trimming the HTML templates, joining the split statements, creating the output folders if needed and watching the Generis files for modifications.

Version

2.0

Author: Senselogic
Source Code: https://github.com/senselogic/GENERIS
License: View license

#go #golang #code

Elian Harber

1620316020

Writing Custom Linter in Go

Writing linters is simple. I was surprised how it’s easy to write a Go linter. Today, we’ll write a linter that will calculate the cyclomatic complexity of the Go code.

What is cyclomatic complexity?

Cyclomatic complexity is a software metric used to indicate the complexity of a program. ref

The idea is simple — every time we find any control flow statements we increase the complexity by one. I know I oversimplified it a bit but I don’t want to overwhelm you with unnecessary details.

There are a few steps we should follow to write our custom linter. Firstly, we can create a test that will check if our linter works or not. Let’s put him into pkg/analyzer/analyzer_test.go file.

package analyzer

import (
	"os"
	"path/filepath"
	"testing"

	"golang.org/x/tools/go/analysis/analysistest"
)

func TestAll(t *testing.T) {
	wd, err := os.Getwd()
	if err != nil {
		t.Fatalf("Failed to get wd: %s", err)
	}

	testdata := filepath.Join(filepath.Dir(filepath.Dir(wd)), "testdata")
	analysistest.Run(t, testdata, NewAnalyzer(), "complexity")
}

The analysistest.Run() function is a helper that simplifies testing linters. What it does is running our linter on package complexity in testate folder. We use NewAnalyzer() function that will return instance of our analyzer. Let’s add it to pkg/analyzer/analyzer.go.

#go #golang #linter

Fynzo Survey

1622049211

Fynzo Customer Feedback Software For Cafes, Hotels, Saloons, Spa!

Customer Feedback Tool | Fynzo online customer feedback comes with Android, iOS app. Collect feedback from your customers with tablets or send them feedback links.

Visit page for more information: https://www.fynzo.com/feedback

#CustomerFeedbackSystem
#PowerfulCustomerFeedbackSystem
#freecustomerfeedbacktools
#automatedcustomerfeedbacksystem
#customerfeedbacktools
#customerratingsystem
#Customerfeedbackmanagement

#customer feedback system #powerful customer feedback system #free customer feedback tools #automated customer feedback system #customer feedback tools #customer rating system

Erwin Boyer

1625278620

Is Tech Making or Breaking Your Customer Experience?

Technology can be a two-edged sword. It can deliver incredible results and create unique problems. The customer experience (CX) sector, in particular, has been heavily impacted by technology for quite some time.

Just because you’re using customer relationship management (CRM) tech, doesn’t mean it’s working, though. Here are a few questions to ask yourself to see if your tech is making or breaking your customer’s experience.

Is Your Customer Service Organized?

Are You Ignoring Phone Calls for Other Tech?

Is Your Customer Experience too Tech-Centric?

Is Your Customer Experience Obsessed with Speed?

…

#customer-experience #customer-service #technology #tech #customer-support #customer-engagement #bus #customer-support-chatbots