fix-csp-compliance

Fix CSP Compliance - Unsafe Inline Scripts

Key Rules

1. NEVER delete inline script content. Always extract it to an external .js file and replace the inline <script>...</script> with <script src="filename.js"></script>. Even trivial config objects, debug flags, or seemingly unused code must be externalized — removal is a functional regression.
2. File naming: use a descriptive name matching the content's purpose (e.g., appConfig.js for configuration, init.js for initialization).

This skill fixes Content Security Policy (CSP) compliance issues that the UI5 linter detects but cannot auto-fix because they require restructuring code into external files.

Linter Rule Handled

Rule ID	Message Pattern	Severity	This Skill's Action
csp-unsafe-inline-script	Use of unsafe inline script	Warning	Move to external JS file

When to Use

Apply this skill when you see linter output like:

index.html:15:5 warning Use of unsafe inline script  csp-unsafe-inline-script
test.html:20:5 warning Use of unsafe inline script  csp-unsafe-inline-script

Background: Why CSP Matters

Content Security Policy (CSP) is a security feature that helps prevent:

• Cross-Site Scripting (XSS) attacks
• Data injection attacks
• Unauthorized script execution

Inline scripts are considered unsafe because an attacker who manages to inject HTML can also inject malicious JavaScript. CSP-compliant apps use script-src 'self' which blocks inline scripts.

Documentation: Content Security Policy

Detection

The linter flags <script> tags that:

• Have NO src attribute AND
• Have inline JavaScript content

Flagged:

<script>
    console.log("Inline code");  <!-- Flagged -->
</script>

<script type="text/javascript">
    doSomething();  <!-- Flagged -->
</script>

<script type="module">
    import { foo } from './foo.js';  <!-- Flagged -->
</script>

Not flagged:

<script src="app.js"></script>  <!-- External = OK -->

<script src="app.js">
    // This content is ignored by browser anyway
</script>

<script type="text/xmldata">
    <!-- Non-JS MIME type = OK -->
    <data>...</data>
</script>

Fix Strategy

The fix for every inline script is the same: move it to an external file and add a <script src="..."> tag in its place. The content of the inline script is preserved — just in a separate .js file instead of inside the HTML. Never delete inline script content; always externalize it.

---

1. Basic Inline Script → External File

Problem: Inline JavaScript in HTML.

<!-- Before - index.html -->
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>My App</title>
    <script>
        window.myConfig = {
            apiUrl: "/api/v1",
            debug: true
        };
    </script>
    <script
        id="sap-ui-bootstrap"
        src="resources/sap-ui-core.js"
        data-sap-ui-async="true">
    </script>
    <script>
        sap.ui.require(["my/app/init"], function(init) {
            init.start();
        });
    </script>
</head>
<body class="sapUiBody" id="content">
</body>
</html>

Fix Strategy: Move inline scripts to external files.

<!-- After - index.html -->
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>My App</title>
    <script src="config.js"></script>
    <script
        id="sap-ui-bootstrap"
        src="resources/sap-ui-core.js"
        data-sap-ui-async="true"
        data-sap-ui-on-init="module:my/app/init">
    </script>
</head>
<body class="sapUiBody" id="content">
</body>
</html>

// config.js
window.myConfig = {
    apiUrl: "/api/v1",
    debug: true
};

// my/app/init.js
sap.ui.define([], function() {
    "use strict";

    return {
        start: function() {
            // Initialization code
        }
    };
});

2. UI5 Bootstrap with Inline Init → data-sap-ui-on-init

Problem: Inline script after UI5 bootstrap.

<!-- Before -->
<script
    id="sap-ui-bootstrap"
    src="resources/sap-ui-core.js"
    data-sap-ui-async="true"
    data-sap-ui-resource-roots='{"my.app": "./"}'
    data-sap-ui-compat-version="edge">
</script>
<script>
    sap.ui.getCore().attachInit(function() {
        sap.ui.require([
            "sap/m/Shell",
            "sap/ui/core/ComponentContainer"
        ], function(Shell, ComponentContainer) {
            new Shell({
                app: new ComponentContainer({
                    name: "my.app",
                    async: true
                })
            }).placeAt("content");
        });
    });
</script>

Fix Strategy: Use data-sap-ui-on-init attribute.

<!-- After - index.html -->
<script
    id="sap-ui-bootstrap"
    src="resources/sap-ui-core.js"
    data-sap-ui-async="true"
    data-sap-ui-resource-roots='{"my.app": "./"}'
    data-sap-ui-compat-version="edge"
    data-sap-ui-on-init="module:my/app/init">
</script>

// webapp/init.js
sap.ui.define([
    "sap/m/Shell",
    "sap/ui/core/ComponentContainer"
], function(Shell, ComponentContainer) {
    "use strict";

    new Shell({
        app: new ComponentContainer({
            name: "my.app",
            async: true
        })
    }).placeAt("content");
});

3. Configuration Data → JSON or Module

Problem: Inline configuration object.

<!-- Before -->
<script>
    window.APP_CONFIG = {
        apiEndpoint: "https://api.example.com",
        features: {
            darkMode: true,
            analytics: false
        }
    };
</script>

Fix Strategy A: External JSON file loaded at runtime.

<!-- After - Option A: JSON file -->
<script src="config.js"></script>

// config.js - loads JSON
(function() {
    var xhr = new XMLHttpRequest();
    xhr.open("GET", "config.json", false);  // Sync for config
    xhr.send();
    window.APP_CONFIG = JSON.parse(xhr.responseText);
})();

// config.json
{
    "apiEndpoint": "https://api.example.com",
    "features": {
        "darkMode": true,
        "analytics": false
    }
}

Fix Strategy B: UI5 module with configuration.

// my/app/config.js
sap.ui.define([], function() {
    "use strict";

    return {
        apiEndpoint: "https://api.example.com",
        features: {
            darkMode: true,
            analytics: false
        }
    };
});

// Usage in other modules
sap.ui.define(["my/app/config"], function(config) {
    console.log(config.apiEndpoint);
});

4. Inline Event Handlers → External Scripts

Problem: Inline event handlers in HTML attributes.

<!-- Before -->
<button onclick="handleClick()">Click me</button>
<img src="logo.png" onerror="handleError(this)">
<body onload="init()">

Fix Strategy: Use external script with event listeners.

<!-- After -->
<button id="myButton">Click me</button>
<img id="logo" src="logo.png">
<body>

// app.js
document.addEventListener("DOMContentLoaded", function() {
    document.getElementById("myButton").addEventListener("click", handleClick);
    document.getElementById("logo").addEventListener("error", function() {
        handleError(this);
    });
    init();
});

function handleClick() {
    // Click handler
}

function handleError(element) {
    // Error handler
}

function init() {
    // Initialization
}

5. Test HTML Files

Problem: QUnit test files with inline scripts.

<!-- Before - myTest.qunit.html -->
<!DOCTYPE html>
<html>
<head>
    <script src="resources/sap-ui-core.js"
        data-sap-ui-async="true">
    </script>
    <script>
        sap.ui.getCore().attachInit(function() {
            sap.ui.require(["my/app/test/myTest"]);
        });
    </script>
</head>
<body>
    <div id="qunit"></div>
</body>
</html>

Fix Strategy: Use Test Starter (also fixes prefer-test-starter).

<!-- After - myTest.qunit.html -->
<!DOCTYPE html>
<html>
<head>
    <script
        src="resources/sap/ui/test/starter/runTest.js"
        data-sap-ui-testsuite="test-resources/my/app/test/testsuite.qunit">
    </script>
</head>
<body>
    <div id="qunit"></div>
</body>
</html>

6. Dynamic Script Content

Problem: Script content generated dynamically.

<!-- Before -->
<script>
    var userId = "<%= user.id %>";  // Server-side template
    var token = "<?php echo $token; ?>";
</script>

Fix Strategy: Use data attributes or meta tags.

<!-- After -->
<meta name="user-id" content="<%= user.id %>">
<meta name="csrf-token" content="<?php echo $token; ?>">
<script src="app.js"></script>

// app.js
var userId = document.querySelector('meta[name="user-id"]').content;
var token = document.querySelector('meta[name="csrf-token"]').content;

Implementation Steps

1. Identify all inline scripts from linter output

2. Categorize each script:

   • UI5 initialization → Use data-sap-ui-on-init
   • Configuration → External JS file
   • Event handlers → External script with addEventListener
   • Test boilerplate → Use Test Starter

3. Create external files for the script content

4. Update HTML to reference external files

5. Test the application to ensure functionality is preserved

Common Patterns

Inline Pattern	CSP-Compliant Solution
<script>code</script>	<script src="file.js">
data-sap-ui-on-init with inline	data-sap-ui-on-init="module:path/to/init"
onclick="fn()"	element.addEventListener("click", fn)
onerror="fn()"	element.addEventListener("error", fn)
onload="fn()"	DOMContentLoaded event listener
Server-rendered config	<meta> tags + JS reader
QUnit inline bootstrap	Test Starter runTest.js

Notes

• CSP compliance is a warning (not error) because some environments may not require it
• The data-sap-ui-on-init attribute accepts module:path/to/module format for AMD modules
• For server-rendered dynamic values, use <meta> tags or data-* attributes
• Test files should use Test Starter for both CSP compliance and best practices
• Some third-party libraries may require CSP adjustments - check their documentation
• JSONP callbacks may need special handling in CSP configurations