[Ruleset Engine] Add remove_query_args() function (#23799)

Author: pedrosousa

src/content/docs/ruleset-engine/rules-language/functions.mdx

@@ -73,7 +73,7 @@ Examples:
 - If `ip.src` is `113.10.0.2`, `cidr(ip.src, 24, 24)` will return `113.10.0.0`.
 - If `ip.src` is `2001:0000:130F:0000:0000:09C0:876A:130B`, `cidr(ip.src, 24, 24)` will return `2001:0000:0000:0000:0000:0000:0000:0000`.
 
-:::caution
+:::note
 You can only use the `cidr()` function in [custom rules](/waf/custom-rules/) and [rate limiting rules](/waf/rate-limiting-rules/).
 :::
 
@@ -95,7 +95,7 @@ Examples:
 - If `ip.src` is `2001:0000:130F:0000:0000:09C0:876A:130B`, `cidr6(ip.src, 24)` will return `2001:0000:0000:0000:0000:0000:0000:0000`.
 - If `ip.src` is `113.10.0.2`, `cidr6(ip.src, 24)` will return `113.10.0.2` (unchanged).
 
-:::caution
+:::note
 You can only use the `cidr6()` function in [custom rules](/waf/custom-rules/) and [rate limiting rules](/waf/rate-limiting-rules/).
 :::
 
@@ -104,7 +104,7 @@ You can only use the `cidr6()` function in [custom rules](/waf/custom-rules/) an
 {/* prettier-ignore */}
 <code>concat(<Type text="String | Bytes | Array" />)</code>: <Type text="String | Array" />
 
-Takes a comma-separated list of values. Concatenates the argument values into a single String or array. 
+Takes a comma-separated list of values. Concatenates the argument values into a single String or array.
 
 The return type depends on the type of input arguments. For example, if you concatenate arrays, the function will return an array.
 
@@ -121,7 +121,7 @@ Decodes a Base64-encoded String specified in `source`.
 
 For example, with the following HTTP request header: `client_id: MTIzYWJj`, `(any(decode_base64(http.request.headers["client_id"][*])[*] eq "123abc"))` would return `true`.
 
-:::caution
+:::note
 You can only use the `decode_base64()` function in [header transform rules](/rules/transform/), [custom rules](/waf/custom-rules/), and [rate limiting rules](/waf/rate-limiting-rules/).
 :::
 
@@ -249,7 +249,7 @@ Examples:
 
 Create capture groups by putting part of the regular expression in parentheses. Then, reference a capture group using `${<NUMBER>}` in the replacement string, where `<NUMBER>` is the number of the capture group.
 
-:::caution
+:::note
 You can only use the `regex_replace()` function in rewrite expressions of [Transform Rules](/rules/transform/) and target URL expressions of [dynamic URL redirects](/rules/url-forwarding/single-redirects/).
 :::
 
@@ -262,6 +262,43 @@ Returns a new byte array with all the occurrences of the given bytes removed.
 
 For example, if `http.host` is `"www.cloudflare.com"`, then `remove_bytes(http.host, "\x2e\x77")` will return `"cloudflarecom"`.
 
+### `remove_query_args`
+
+{/* prettier-ignore */}
+<code>remove_query_args(field <Type text="String" />, query_param1 <Type text="String" />, query_param2 <Type text="String" />, ...)</code>: <Type text="String" />
+
+Removes one or more query string parameters from a URI query string. Returns a string without the specified parameters.
+
+The `field` must be one of the following:
+
+- `http.request.uri.query`
+- `raw.http.request.uri.query`
+
+The `field` cannot be a literal value such as `"search=foo&order=asc"`.
+
+The `remove_query_args()` function will remove all specified parameters (as `query_param1`, `query_param2`, etc.) , including repeated occurrences of the same parameter.
+
+The ordering of unaffected query parameters will be preserved.
+
+Examples:
+
+```txt
+// If http.request.uri.query is "order=asc&country=GB":
+
+remove_query_args(http.request.uri.query, "country")  will return "order=asc"
+remove_query_args(http.request.uri.query, "order")    will return "country=GB"
+remove_query_args(http.request.uri.query, "search")   will return "order=asc&country=GB" (unchanged)
+
+// If http.request.uri.query is "category=Foo&order=desc&category=Bar":
+
+remove_query_args(http.request.uri.query, "order")    will return "category=Foo&category=Bar"
+remove_query_args(http.request.uri.query, "category") will return "order=desc"
+```
+
+:::note
+You can only use the `remove_query_args()` function in [rewrite expressions of Transform Rules](/rules/transform/).
+:::
+
 ### `starts_with`
 
 {/* prettier-ignore */}
@@ -308,7 +345,7 @@ to_string(cf.bot_management.score)   will return "5"
 to_string(ssl)                       will return "true"
 ```
 
-:::caution
+:::note
 You can only use the `to_string()` function in rewrite expressions of [Transform Rules](/rules/transform/) and target URL expressions of [dynamic URL redirects](/rules/url-forwarding/single-redirects/).
 :::
 
@@ -363,7 +400,7 @@ Generates a random UUIDv4 (Universally Unique Identifier, version 4) based on th
 
 For example, `uuidv4(cf.random_seed)` will return a UUIDv4 similar to `49887398-6bcf-485f-8899-f15dbef4d1d5`.
 
-:::caution
+:::note
 You can only use the `uuidv4()` function in [rewrite expressions of Transform Rules](/rules/transform/).
 :::
 
@@ -408,7 +445,7 @@ Examples:
 
 For more examples of wildcard matching, refer to [Wildcard matching](/ruleset-engine/rules-language/operators/#wildcard-matching).
 
-:::caution
+:::note
 Currently, you can only use the `wildcard_replace()` function in rewrite expressions of [URL rewrites](/rules/transform/url-rewrite/) and target URL expressions of [dynamic URL redirects](/rules/url-forwarding/single-redirects/).
 :::
 
@@ -453,27 +490,21 @@ is_timed_hmac_valid_v0(
 The `is_timed_hmac_valid_v0()` function has these parameter definitions:
 
 - `Key` <Type text="String literal" />
-
   - Specifies the secret cryptographic key for validating the HMAC.
 
 - `MessageMAC` <Type text="String" />
-
   - Contains a concatenation of these HMAC elements: `message`, `separator`, `timestamp`, `mac`. For a definition and an example, refer to [MessageMAC](#messagemac).
 
 - `ttl` <Type text="Integer literal" />
-
   - Defines the time-to-live for the HMAC token, expressed in seconds. Determines how long the token is valid, relative to the time it was issued.
 
 - `currentTimeStamp` <Type text="Integer" />
-
   - Represents the UNIX timestamp when Cloudflare received the request, expressed in seconds. Pass the `http.request.timestamp.sec` field as an approximate value to this argument.
 
 - `lengthOfSeparator` <Type text="Integer literal" /> <MetaInfo text='optional' />
-
   - Specifies the length of the `separator` between the `timestamp` and the `message` in the `MessageMAC`. Expressed in bytes, with a default value of `0`.
 
 - `flags` <Type text="String literal" /> <MetaInfo text='optional' />
-
   - When you set this optional argument to `'s'`, the function expects the value of the Base64-encoded `mac` in the `MessageMAC` argument to use the URL-safe character set with no padding.
 
   - When you do **not** set the value of `flags` to `'s'`, you must URL encode the Base64 value for `mac` in the `MessageMAC` argument.
@@ -512,7 +543,7 @@ For details on generating a MessageMAC, refer to [HMAC token generation](/waf/cu
 
 ## HMAC validation examples
 
-:::caution[Important]
+:::note
 
 When you do not use the optional `flags` argument for `is_timed_hmac_valid_v0()`, you must URL-encode the Base64 value for `mac` in the `MessageMAC` argument.