//CallrunCodetorunthetemplate's code with a lowercase stringletvariableResult=runCode({text1:'this is a test'});//ValidatethattheresultofrunCodeisanuppercasestring.assertThat(variableResult).isEqualTo('THIS IS A TEST');
此测试会将字符串 'this is a test' 传递给变量,并验证该变量是否返回预期的 'THIS IS A TEST' 字符串值。runCode API 用于运行代码标签中的模板代码。runCode 的参数是一个可用作全局数据的对象。assertThat API 会返回一个对象,可用于顺畅地对主题的值进行断言。
[null,null,["最后更新时间 (UTC):2025-07-25。"],[[["\u003cp\u003eGoogle Tag Manager uses unit tests to validate custom template functionality before deployment.\u003c/p\u003e\n"],["\u003cp\u003eUnit tests for custom templates utilize sample inputs, mock functions, and assertions to verify code behavior.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003erunCode\u003c/code\u003e API executes the template's code within the test environment, while \u003ccode\u003eassertThat\u003c/code\u003e verifies the output against expected values.\u003c/p\u003e\n"],["\u003cp\u003eThese tests help identify and address potential issues, such as handling undefined or unexpected inputs, before deploying the template.\u003c/p\u003e\n"],["\u003cp\u003eBy creating and running unit tests for your custom templates, you can improve the reliability and stability of your Google Tag Manager implementations.\u003c/p\u003e\n"]]],["Unit tests for Google Tag Manager templates validate functionality by running tests without deployment. You create tests within the template editor under the \"Tests\" tab. Tests use `runCode` to simulate template execution with sample data and `assertThat` to verify results. The process involves creating a template, adding input fields, writing code, and creating tests to handle various inputs. Tests can be run individually or collectively. Limitations are that Unit tests do not check validation rules and permission checks do not happen.\n"],null,["# Tests\n\nUnit tests for Google Tag Manager custom templates help you validate the functionality of your templates. You can create a set of tests for each template\nthat can be run without needing to deploy your tag, which allows you to\ncontinuously test your template's behavior during development. Each test can\nprovide sample input values, mock function calls, and assert code behavior.\n\nLimitations\n-----------\n\n- Unit tests do not check validation rules but you can manually check validation using the **Run Code** button.\n- Permission checks do not happen on mocked APIs in unit tests.\n\nThis guide will walk you through how to write unit tests for your custom template. This example creates a variable template that takes an input string and returns\nthe uppercase version of that string.\n\n1. Create a new variable template. Click **Templates** in the left navigation and click **New** under the **Variable Templates** section.\n\n2. Click **Fields**.\n\n3. Click **Add Field** and select **Text input** . Name the field `text1` and set the display name to *\"Text 1\"*.\n\n4. In the **Code** tab, replace the default code with this sandboxed JavaScript:\n\n let input = data.text1;\n return input.toUpperCase();\n\n5. Click **Tests** to open the testing tab.\n\n6. Click **Add Test** and change the test's name from *\"Untitled test 1\"* to *\"Handles strings\"*.\n\n7. Click on the expand icon (*expand_more*) to reveal the test's sandboxed JavaScript editor. Replace the code with this sandboxed JavaScript:\n\n // Call runCode to run the template's code with a lowercase string\n let variableResult = runCode({text1: 'this is a test'});\n // Validate that the result of runCode is an uppercase string.\n assertThat(variableResult).isEqualTo('THIS IS A TEST');\n\n This test passes the string *`'this is a test'`* to the variable and verifies that the variable returns the expected value of *`'THIS IS A TEST'`* . The [`runCode`](/tag-platform/tag-manager/templates/api#runcode) API is used to run the template code in the **Code** tab. The argument to `runCode` is an object that is used as the data global. The [`assertThat`](/tag-platform/tag-manager/templates/api#assertthat) API returns an object that can be used to fluently make assertions about a subject's value.\n8. Click **▶ Run Tests** to run the test. The output of the test will appear in the Console.\n\n The **▶ Run Tests** button runs all of the enabled tests in the template, in the order shown. To change the order, use the drag icon (⠿). A test can be temporarily enabled or disabled by clicking on the circle to the left of the test name. To run a single test, click the ▶ button that appears when you move the mouse over the test.\n\n The console should print the total number of tests run and the number of tests that failed, if any. In this case, only one test was run and it should pass.\n9. Click **Add Test** again to add a second test. Change the test's name from *\"Untitled test 2\"* to *\"Handles undefined\"*.\n\n10. Click on the test to expand it and reveal the sandboxed JavaScript editor. Enter sandboxed JavaScript in the editor:\n\n let variableResult = runCode({});\n assertThat(variableResult).isEqualTo(undefined);\n\n | **Note:** [`runCode`](/tag-platform/tag-manager/templates/api#runcode) is called with an empty object, which means the value of the `text1` field will be `undefined` in this test case.\n11. Click **▶ Run Tests** to run all of the tests at once. The output of the test will appear in the console.\n\n The *Handles undefined* test should fail. Congratulations, you found a bug!\n12. Click **Code** to go back and edit the template's sandboxed JavaScript code. Update the sandboxed JavaScript as follows:\n\n const getType = require('getType');\n\n let input = data.text1;\n if (getType(input) !== 'string') {\n return input;\n }\n return input.toUpperCase();\n\n The updated code follows the best practice of validating the `input` variable before using it.\n13. Click **Tests** to go back to the list of test cases.\n\n14. Click **▶ Run Tests** to run all of the test cases again. This time the *Handles undefined* test should pass.\n\n15. Click **Save**, and close the Template Editor."]]