1 files changed, 101 insertions, 0 deletions
diff --git a/toolkit/modules/tests/modules/MockDocument.sys.mjs b/toolkit/modules/tests/modules/MockDocument.sys.mjs
new file mode 100644
index 0000000000..efcb6360ba
--- /dev/null
+++ b/toolkit/modules/tests/modules/MockDocument.sys.mjs
@@ -0,0 +1,101 @@
+/**
+ * Provides infrastructure for tests that would require mock document.
+ */
+
+const { NetUtil } = ChromeUtils.import("resource://gre/modules/NetUtil.jsm");
+
+export const MockDocument = {
+  /**
+   * Create a document for the given URL containing the given HTML with the ownerDocument of all <form>s having a mocked location.
+   */
+  createTestDocument(
+    aDocumentURL,
+    aContent = "<form>",
+    aType = "text/html",
+    useSystemPrincipal = false
+  ) {
+    let parser = new DOMParser();
+    let parsedDoc;
+    if (useSystemPrincipal) {
+      parsedDoc = parser.parseFromSafeString(aContent, aType);
+    } else {
+      parsedDoc = parser.parseFromString(aContent, aType);
+    }
+
+    // Assign ownerGlobal to documentElement as well for the form-less
+    // inputs treating it as rootElement.
+    this.mockOwnerGlobalProperty(parsedDoc.documentElement);
+
+    for (let form of parsedDoc.forms) {
+      this.mockOwnerDocumentProperty(form, parsedDoc, aDocumentURL);
+      this.mockOwnerGlobalProperty(form);
+      for (let field of form.elements) {
+        this.mockOwnerGlobalProperty(field);
+      }
+    }
+    return parsedDoc;
+  },
+
+  mockOwnerDocumentProperty(aElement, aDoc, aURL) {
+    // Mock the document.location object so we can unit test without a frame. We use a proxy
+    // instead of just assigning to the property since it's not configurable or writable.
+    let document = new Proxy(aDoc, {
+      get(target, property, receiver) {
+        // document.location is normally null when a document is outside of a "browsing context".
+        // See https://html.spec.whatwg.org/#the-location-interface
+        if (property == "location") {
+          return new URL(aURL);
+        }
+        return target[property];
+      },
+    });
+
+    // Assign element.ownerDocument to the proxy so document.location works.
+    Object.defineProperty(aElement, "ownerDocument", {
+      value: document,
+    });
+  },
+
+  mockOwnerGlobalProperty(aElement) {
+    Object.defineProperty(aElement, "ownerGlobal", {
+      value: {
+        windowUtils: {
+          addManuallyManagedState() {},
+          removeManuallyManagedState() {},
+        },
+        UIEvent: Event,
+        Event,
+      },
+      configurable: true,
+    });
+  },
+
+  mockNodePrincipalProperty(aElement, aURL) {
+    Object.defineProperty(aElement, "nodePrincipal", {
+      value: Services.scriptSecurityManager.createContentPrincipal(
+        Services.io.newURI(aURL),
+        {}
+      ),
+    });
+  },
+
+  mockBrowsingContextProperty(aElement, aBC) {
+    Object.defineProperty(aElement, "browsingContext", {
+      value: aBC,
+    });
+  },
+
+  createTestDocumentFromFile(aDocumentURL, aFile) {
+    let fileStream = Cc[
+      "@mozilla.org/network/file-input-stream;1"
+    ].createInstance(Ci.nsIFileInputStream);
+    fileStream.init(aFile, -1, -1, 0);
+
+    let data = NetUtil.readInputStreamToString(
+      fileStream,
+      fileStream.available()
+    );
+
+    return this.createTestDocument(aDocumentURL, data);
+  },
+};