From ac1421e8d5eab97159f009c4b8b41c0b882f8b9a Mon Sep 17 00:00:00 2001
From: "Alex N. Jose" <alexnj@users.noreply.github.com>
Date: Wed, 10 Jan 2024 11:19:54 -0800
Subject: [PATCH] Implement Redirect operation - Pre-UA and On-UA
 implementations (#17)

* Redirect op first cut

* Markdown updates

---------

Co-authored-by: Micah Heineck <micah.heineck@optimizely.com>
---
 sdks/npm/src/cf/on-ua-applicator.ts  |  8 ++-
 sdks/npm/src/cf/pre-ua-applicator.ts |  6 ++
 specs/EXPLAINER.md                   | 88 ++++++++++------------------
 3 files changed, 42 insertions(+), 60 deletions(-)

diff --git a/sdks/npm/src/cf/on-ua-applicator.ts b/sdks/npm/src/cf/on-ua-applicator.ts
index 785059f..a1ac740 100644
--- a/sdks/npm/src/cf/on-ua-applicator.ts
+++ b/sdks/npm/src/cf/on-ua-applicator.ts
@@ -8,8 +8,12 @@ export default class UATransformApplicator  implements HTMLRewriterElementConten
   }
 
   static serializeOperation(operation: Experimentation.Operations, args: any[]) {
-    if (operation === Experimentation.Operations.CustomJs) {
-      return [operation, `$=>{${args[0]}}`];
+    switch (operation) {
+      case Experimentation.Operations.CustomJs:
+        return [operation, `$=>{${args[0]}}`];
+      case Experimentation.Operations.Redirect:
+        // In case of a redirect, we use a CustomJs operation to rewrite location.
+        return [Experimentation.Operations.CustomJs, `$=>{window.location.href="${JSON.stringify(args[0])}"}`];
     }
     return [operation, ...args.map(arg => JSON.stringify(arg))];
   }
diff --git a/sdks/npm/src/cf/pre-ua-applicator.ts b/sdks/npm/src/cf/pre-ua-applicator.ts
index 693c6c9..82f0330 100644
--- a/sdks/npm/src/cf/pre-ua-applicator.ts
+++ b/sdks/npm/src/cf/pre-ua-applicator.ts
@@ -37,5 +37,11 @@ export default class PreUATransformApplicator implements HTMLRewriterElementCont
     }
 
     // Handle any complex operations that involves multiple CF operations.
+    switch (this.op) {
+      case Experimentation.Operations.Redirect:
+        const [url, code] = this.args;
+        Response.redirect(url, code);
+        break;
+    }
   }
 }
\ No newline at end of file
diff --git a/specs/EXPLAINER.md b/specs/EXPLAINER.md
index 210deb5..40f6211 100644
--- a/specs/EXPLAINER.md
+++ b/specs/EXPLAINER.md
@@ -109,25 +109,22 @@ where each field can be defined as follows
    <td style="background-color: #d9d9d9">Operation</td>
    <td style="background-color: #d9d9d9">Code</td>
    <td style="background-color: #d9d9d9">Description</td>
+   <td style="background-color: #d9d9d9">Arguments</td>
   </tr>
   <tr>
    <td>OP_CUSTOM_JS</td>
    <td>0</td>
    <td>Executes a custom Javascript block of code against the element.
-<p>
-
-Arguments:
-
-`code`: Javascript code serialized as a string. The applicator code will call this code as a function ($) => code, $ referring to the element selected.
+   <td> 
+   
+   `code` : Javascript code serialized as a string. The applicator code will call this code as a function ($) => code, $ referring to the element selected.
    </td>
   </tr>
   <tr>
    <td>OP_INSERT_BEFORE</td>
    <td>1</td>
-   <td>Inserts content right before the element.
-<p>
-
-Arguments:
+   <td>Inserts content right before the element.</td>
+<td>
 
 `content`: HTML markup
    </td>
@@ -135,99 +132,74 @@ Arguments:
   <tr>
    <td>OP_INSERT_AFTER</td>
    <td>2</td>
-   <td>Inserts content right after the element.
-<p>
+   <td>Inserts content right after the element.</td>
+<td>
 
-Arguments:
-
-<p>
 `content`: HTML markup
    </td>
   </tr>
   <tr>
    <td>OP_PREPEND</td>
    <td>3</td>
-   <td>Inserts content right after the start tag of the element.
-<p>
-
-Arguments:
-
-<p>
-`content`: HTML markup
+   <td>Inserts content right after the start tag of the element.</td>
+   <td> 
+   
+   `content`: HTML markup
    </td>
   </tr>
   <tr>
    <td>OP_APPEND</td>
    <td>4</td>
-   <td>Inserts content right before the end tag of the element.
-<p>
-
-Arguments:
+   <td>Inserts content right before the end tag of the element.</td>
+   <td> 
 
-<p>
 `content`: HTML markup
    </td>
   </tr>
   <tr>
    <td>OP_REPLACE</td>
    <td>5</td>
-   <td>Replaces the element with the provided content.
-<p>
+   <td>Replaces the element with the provided content.</td>
+   <td> 
 
-Arguments:
-
-<p>
 `content`: HTML markup
    </td>
   </tr>
   <tr>
    <td>OP_SET_INNERHTML</td>
    <td>6</td>
-   <td>Replaces the content of the element with provided content.
-<p>
-
-Arguments:
-
-<p>
+   <td>Replaces the content of the element with provided content.</td>
+   <td> 
+   
 `content`: HTML markup
    </td>
   </tr>
   <tr>
    <td>OP_REMOVE</td>
    <td>7</td>
-   <td>Removes the element and its children
-<p>
-
-Arguments:
-
-<p>
-none.
-   </td>
+   <td>Removes the element and its children</td>
+   <td>none</td>
   </tr>
   <tr>
    <td>OP_SET_ATTRIBUTE</td>
    <td>8</td>
-   <td>Sets an attribute’s value on the element.
-<p>
-
-Arguments:
-
-<p>
+   <td>Sets an attribute’s value on the element.</td>
+   <td> 
+   
 `name`: Name of the attribute
-<p>
+
 `value`: Value to be set on the attribute.
    </td>
   </tr>
   <tr>
    <td>OP_REDIRECT</td>
    <td>9</td>
-   <td>Redirect the user to a different page or URL.
-<p>
-
-Arguments:
-
-<p>
+   <td>Redirect the user to a different page or URL. During `PRE_UA` phase, this will perform an HTTP redirect and during `ON_UA`, this will result in client side redirection. Additional arguments supplied can select the response code during PRE_UA phase.</td>
+   <td> 
+   
 `URL`: URL to redirect the page to.
+
+`code`: HTTP code to use for redirection during PRE_UA phase.
    </td>
   </tr>
 </table>