API 測試

簡介

Playwright 可以用來存取你的應用程式的 REST API。

有時你可能想直接從 .NET 發送請求到伺服器，而不需要載入頁面並在其中執行 js 程式碼。以下是一些可能會派上用場的範例:

• 測試你的伺服器 API。
• 在測試中訪問 web 應用程式之前準備伺服器端狀態。
• 在瀏覽器中執行一些操作後驗證伺服器端後置條件。

所有這些都可以通過 APIRequestContext 方法實現。

以下範例依賴 Microsoft.Playwright.MSTest 套件，它為每個測試建立一個 Playwright 和 Page 實例。

撰寫 API 測試

APIRequestContext 可以透過網路發送各種 HTTP(S) 請求。

以下範例展示如何使用 Playwright 測試通過 GitHub API 建立問題。測試套件將執行以下操作：

• 建立一個新的儲存庫後執行測試。
• 建立一些問題並驗證伺服器狀態。
• 執行測試後刪除儲存庫。

設定

GitHub API 需要授權，所以我們將為所有測試設定一次 token。在此同時，我們也會設定 baseURL 來簡化測試。

using Microsoft.Playwright;
using Microsoft.Playwright.MSTest;

namespace PlaywrightTests;

[TestClass]
public class TestGitHubAPI : PlaywrightTest
{
    static string? API_TOKEN = Environment.GetEnvironmentVariable("GITHUB_API_TOKEN");

    private IAPIRequestContext Request = null!;

    [TestInitialize]
    public async Task SetUpAPITesting()
    {
        await CreateAPIRequestContext();
    }

    private async Task CreateAPIRequestContext()
    {
        var headers = new Dictionary<string, string>();
        // We set this header per GitHub guidelines.
        headers.Add("Accept", "application/vnd.github.v3+json");
        // Add authorization token to all requests.
        // Assuming personal access token available in the environment.
        headers.Add("Authorization", "token " + API_TOKEN);

        Request = await this.Playwright.APIRequest.NewContextAsync(new() {
            // All requests we send go to this API endpoint.
            BaseURL = "https://api.github.com",
            ExtraHTTPHeaders = headers,
        });
    }

    [TestCleanup]
    public async Task TearDownAPITesting()
    {
        await Request.DisposeAsync();
    }
}

撰寫測試

現在我們已經初始化了請求物件，我們可以新增一些測試，這些測試將在存放庫中建立新的問題。

using System.Text.Json;
using Microsoft.Playwright;
using Microsoft.Playwright.MSTest;

namespace PlaywrightTests;

[TestClass]
public class TestGitHubAPI : PlaywrightTest
{
    static string REPO = "test";
    static string USER = Environment.GetEnvironmentVariable("GITHUB_USER");
    static string? API_TOKEN = Environment.GetEnvironmentVariable("GITHUB_API_TOKEN");

    private IAPIRequestContext Request = null!;

    [TestMethod]
    public async Task ShouldCreateBugReport()
    {
        var data = new Dictionary<string, string>
        {
            { "title", "[Bug] report 1" },
            { "body", "Bug description" }
        };
        var newIssue = await Request.PostAsync("/repos/" + USER + "/" + REPO + "/issues", new() { DataObject = data });
        await Expect(newIssue).ToBeOKAsync();

        var issues = await Request.GetAsync("/repos/" + USER + "/" + REPO + "/issues");
        await Expect(newIssue).ToBeOKAsync();
        var issuesJsonResponse = await issues.JsonAsync();
        JsonElement? issue = null;
        foreach (JsonElement issueObj in issuesJsonResponse?.EnumerateArray())
        {
            if (issueObj.TryGetProperty("title", out var title) == true)
            {
                if (title.GetString() == "[Bug] report 1")
                {
                    issue = issueObj;
                }
            }
        }
        Assert.IsNotNull(issue);
        Assert.AreEqual("Bug description", issue?.GetProperty("body").GetString());
    }

    [TestMethod]
    public async Task ShouldCreateFeatureRequests()
    {
        var data = new Dictionary<string, string>
        {
            { "title", "[Feature] request 1" },
            { "body", "Feature description" }
        };
        var newIssue = await Request.PostAsync("/repos/" + USER + "/" + REPO + "/issues", new() { DataObject = data });
        await Expect(newIssue).ToBeOKAsync();

        var issues = await Request.GetAsync("/repos/" + USER + "/" + REPO + "/issues");
        await Expect(newIssue).ToBeOKAsync();
        var issuesJsonResponse = await issues.JsonAsync();

        JsonElement? issue = null;
        foreach (JsonElement issueObj in issuesJsonResponse?.EnumerateArray())
        {
            if (issueObj.TryGetProperty("title", out var title) == true)
            {
                if (title.GetString() == "[Feature] request 1")
                {
                    issue = issueObj;
                }
            }
        }
        Assert.IsNotNull(issue);
        Assert.AreEqual("Feature description", issue?.GetProperty("body").GetString());
    }

    // ...
}

設定和拆卸

這些測試假設資源庫已存在。您可能需要在執行測試之前建立一個新的，並在之後刪除它。為此，請使用[SetUp]和[TearDown]鉤子。

using System.Text.Json;
using Microsoft.Playwright;
using Microsoft.Playwright.MSTest;

namespace PlaywrightTests;

[TestClass]
public class TestGitHubAPI : PlaywrightTest
{
    // ...
    [TestInitialize]
    public async Task SetUpAPITesting()
    {
        await CreateAPIRequestContext();
        await CreateTestRepository();
    }

    private async Task CreateTestRepository()
    {
        var resp = await Request.PostAsync("/user/repos", new()
        {
            DataObject = new Dictionary<string, string>()
            {
                ["name"] = REPO,
            },
        });
        await Expect(resp).ToBeOKAsync();
    }

    [TestCleanup]
    public async Task TearDownAPITesting()
    {
        await DeleteTestRepository();
        await Request.DisposeAsync();
    }

    private async Task DeleteTestRepository()
    {
        var resp = await Request.DeleteAsync("/repos/" + USER + "/" + REPO);
        await Expect(resp).ToBeOKAsync();
    }
}

完整測試範例

以下是一個 API 測試的完整範例:

using System.Text.Json;
using Microsoft.Playwright;
using Microsoft.Playwright.MSTest;

namespace PlaywrightTests;

[TestClass]
public class TestGitHubAPI : PlaywrightTest
{
    static string REPO = "test-repo-2";
    static string USER = Environment.GetEnvironmentVariable("GITHUB_USER");
    static string? API_TOKEN = Environment.GetEnvironmentVariable("GITHUB_API_TOKEN");

    private IAPIRequestContext Request = null!;

    [TestMethod]
    public async Task ShouldCreateBugReport()
    {
        var data = new Dictionary<string, string>
        {
            { "title", "[Bug] report 1" },
            { "body", "Bug description" }
        };
        var newIssue = await Request.PostAsync("/repos/" + USER + "/" + REPO + "/issues", new() { DataObject = data });
        await Expect(newIssue).ToBeOKAsync();

        var issues = await Request.GetAsync("/repos/" + USER + "/" + REPO + "/issues");
        await Expect(newIssue).ToBeOKAsync();
        var issuesJsonResponse = await issues.JsonAsync();
        JsonElement? issue = null;
        foreach (JsonElement issueObj in issuesJsonResponse?.EnumerateArray())
        {
            if (issueObj.TryGetProperty("title", out var title) == true)
            {
                if (title.GetString() == "[Bug] report 1")
                {
                    issue = issueObj;
                }
            }
        }
        Assert.IsNotNull(issue);
        Assert.AreEqual("Bug description", issue?.GetProperty("body").GetString());
    }

    [TestMethod]
    public async Task ShouldCreateFeatureRequests()
    {
        var data = new Dictionary<string, string>
        {
            { "title", "[Feature] request 1" },
            { "body", "Feature description" }
        };
        var newIssue = await Request.PostAsync("/repos/" + USER + "/" + REPO + "/issues", new() { DataObject = data });
        await Expect(newIssue).ToBeOKAsync();

        var issues = await Request.GetAsync("/repos/" + USER + "/" + REPO + "/issues");
        await Expect(newIssue).ToBeOKAsync();
        var issuesJsonResponse = await issues.JsonAsync();

        JsonElement? issue = null;
        foreach (JsonElement issueObj in issuesJsonResponse?.EnumerateArray())
        {
            if (issueObj.TryGetProperty("title", out var title) == true)
            {
                if (title.GetString() == "[Feature] request 1")
                {
                    issue = issueObj;
                }
            }
        }
        Assert.IsNotNull(issue);
        Assert.AreEqual("Feature description", issue?.GetProperty("body").GetString());
    }

    [TestInitialize]
    public async Task SetUpAPITesting()
    {
        await CreateAPIRequestContext();
        await CreateTestRepository();
    }

    private async Task CreateAPIRequestContext()
    {
        var headers = new Dictionary<string, string>
        {
            // We set this header per GitHub guidelines.
            { "Accept", "application/vnd.github.v3+json" },
            // Add authorization token to all requests.
            // Assuming personal access token available in the environment.
            { "Authorization", "token " + API_TOKEN }
        };

        Request = await Playwright.APIRequest.NewContextAsync(new()
        {
            // All requests we send go to this API endpoint.
            BaseURL = "https://api.github.com",
            ExtraHTTPHeaders = headers,
        });
    }

    private async Task CreateTestRepository()
    {
        var resp = await Request.PostAsync("/user/repos", new()
        {
            DataObject = new Dictionary<string, string>()
            {
                ["name"] = REPO,
            },
        });
        await Expect(resp).ToBeOKAsync();
    }

    [TestCleanup]
    public async Task TearDownAPITesting()
    {
        await DeleteTestRepository();
        await Request.DisposeAsync();
    }

    private async Task DeleteTestRepository()
    {
        var resp = await Request.DeleteAsync("/repos/" + USER + "/" + REPO);
        await Expect(resp).ToBeOKAsync();
    }
}

通過 API 呼叫準備伺服器狀態

以下測試通過 API 建立一個新問題，然後導航到專案中所有問題的列表，以檢查它是否出現在列表的頂部。檢查是使用 LocatorAssertions 進行的。

class TestGitHubAPI : PageTest
{
    [TestMethod]
    public async Task LastCreatedIssueShouldBeFirstInTheList()
    {
        var data = new Dictionary<string, string>
        {
            { "title", "[Feature] request 1" },
            { "body", "Feature description" }
        };
        var newIssue = await Request.PostAsync("/repos/" + USER + "/" + REPO + "/issues", new() { DataObject = data });
        await Expect(newIssue).ToBeOKAsync();

        // When inheriting from 'PlaywrightTest' it only gives you a Playwright instance. To get a Page instance, either start
        // a browser, context, and page manually or inherit from 'PageTest' which will launch it for you.
        await Page.GotoAsync("https://github.com/" + USER + "/" + REPO + "/issues");
        var firstIssue = Page.Locator("a[data-hovercard-type='issue']").First;
        await Expect(firstIssue).ToHaveTextAsync("[Feature] request 1");
    }
}

執行用戶操作後檢查伺服器狀態

以下測試通過瀏覽器中的使用者介面建立一個新問題，然後通過 API 檢查是否已建立:

// Make sure to extend from PageTest if you want to use the Page class.
class GitHubTests : PageTest
{
    [TestMethod]
    public async Task LastCreatedIssueShouldBeOnTheServer()
    {
        await Page.GotoAsync("https://github.com/" + USER + "/" + REPO + "/issues");
        await Page.Locator("text=New Issue").ClickAsync();
        await Page.Locator("[aria-label='Title']").FillAsync("Bug report 1");
        await Page.Locator("[aria-label='Comment body']").FillAsync("Bug description");
        await Page.Locator("text=Submit new issue").ClickAsync();
        var issueId = Page.Url.Substring(Page.Url.LastIndexOf('/'));

        var newIssue = await Request.GetAsync("https://github.com/" + USER + "/" + REPO + "/issues/" + issueId);
        await Expect(newIssue).ToBeOKAsync();
        StringAssert.Contains(await newIssue.TextAsync(), "Bug report 1");
    }
}

重用身份驗證狀態

Web apps 使用基於 cookie 或基於 token 的身份驗證，已驗證的狀態會儲存為 cookies。Playwright 提供 ApiRequestContext.StorageStateAsync() 方法，可用於從已驗證的 context 中檢索儲存狀態，然後使用該狀態建立新的 context。

儲存狀態在 BrowserContext 和 APIRequestContext 之間是可互換的。你可以使用它通過 API 呼叫登入，然後建立一個已經包含 cookies 的新 context。以下程式碼片段從已驗證的 APIRequestContext 中檢索狀態，並使用該狀態建立一個新的 BrowserContext。

var requestContext = await Playwright.APIRequest.NewContextAsync(new()
{
    HttpCredentials = new()
    {
        Username = "user",
        Password = "passwd"
    },
});
await requestContext.GetAsync("https://api.example.com/login");
// Save storage state into a variable.
var state = await requestContext.StorageStateAsync();

// Create a new context with the saved storage state.
var context = await Browser.NewContextAsync(new() { StorageState = state });