Dev Guide

IoT Edge is written in C# and Rust. The C# development setup is described below. The Rust development setup is described here.

If you want to run tests outside of the pipelines, you will need to be running linux.

Setup

Make sure the following dependencies are installed in your environment before you build IoT Edge code:

Build

Besides using Visual Studio in Windows, you can build by running the build script:

scripts/linux/buildBranch.sh

Binaries are published to target/publish/.

Run unit tests

Besides using Test Explorer in Visual Studio, you can run the unit tests with:

scripts/linux/runTests.sh

Run integration tests

To run integration tests and/or BVTs, make sure the following dependencies are installed in your environment:

The integration tests and BVTs expect to find certain values in an Azure KeyVault (see edge-util/test/Microsoft.Azure.Devices.Edge.Util.Test.Common/settings/base.json). For the tests to access the KeyVault at runtime, a certificate must first be installed in the environment where the tests will run. Install the KeyVault certificate with:

az login # Login and select default subscription, if necessary

scripts/linux/downloadAndInstallCert.sh -v <VaultName> -c <CertName>

Then run the tests either with Test Explorer in Visual Studio IDE, or with:

scripts/linux/runTests.sh "Category=Integration"

The syntax of the "filter" argument is described here. All IoT Edge tests are categorized as one of Unit, Integration, or Bvt.

Run the end-to-end tests

The end-to-end tests are documented here.

Running Code Coverage Checks for Unit Tests Locally (Windows Only)

Currently, Code Coverage Local Checks are supported only in a Windows Environment due to dependency on Microsoft Code Coverage Tools

1. Use Command Prompt to run dotnet test from root directory

dotnet test /p:CollectCoverage=true --filter "Category=Unit" -s CodeCoverage.runsettings --logger:trx --results-directory TestResults

2. Convert *.coverage to *.coveragexml file to generate HTML Reports

dotnet tool install --global dotnet-coverageconverter
dotnet-coverageconverter --CoverageFilesFolder TestResults

3. Generate HTML Report from Coverage Files. The HTML Coverage Files will be generated in reports folder in the root directory

dotnet tool install -g dotnet-reportgenerator-globaltool
reportgenerator "-reports:TestResults\*\*.coveragexml" "-targetdir:report"

Build Edge Hub Container Locally

Sometimes it is useful to build the Edge Hub container locally. If you want to do so you can run the below script:

./scripts/linux/buildLocalEdgeHub.sh --registry-address "$(registry.address)" --version "$(version)"

Attach the VSCode Debugger to EdgeAgent

There is a script in the repo to setup a docker container with the Visual Studio Debugger (vsdbg). After running the script in a container, you can connect the VSCode debugger to a process running in the container. The following example shows how to run the setup script on a Linux IoT Edge device to setup the debugger in the Edge Agent container:

$ scripts/linux/setupContainerDebugger.sh -c edgeAgent -u edgeagentuser

After running the debugger setup script, create a launch.json file in the edgeAgent/.vscode directory. The launch.json file should have the following contents (Note: replace the value in sourceFileMap before running):

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Remote Debug IoT Edge Module (.NET Core)",
            "type": "coreclr",
            "request": "attach",
            "processId": "${command:pickRemoteProcess}",
            "pipeTransport": {
                "pipeProgram": "docker",
                "pipeArgs": [
                    "exec",
                    "-i",
                    "-u",
                    "edgeagentuser"
                    "edgeAgent",
                    "sh",
                    "-c"
                ],
                "debuggerPath": "/root/vsdbg/vsdbg",
                "pipeCwd": "${workspaceFolder}",
                "quoteArgs": true
            },
            "sourceFileMap": {
                "<replace-with-compile-time-path-to-edge-agent-source>": "${workspaceRoot}"
            },
            "symbolOptions": {
                "searchPaths": ["/app"],
                "searchMicrosoftSymbolServer": false,
                "searchNuGetOrgSymbolServer": false
            },
            "justMyCode": true,
            "requireExactSource": true
        }
    ]
}

Start debugging by selecting the configuration defined above from the 'Run and Debug' tab (Ctrl+Shift+D) and selecting the 'Start Debugging' button (F5).