Add the browser send proxy and web sender

crates-server/yaak-send-proxy: a stateless executor over yaak-http's
HttpTransaction. It takes a rendered request, streams timeline events,
the response head, body chunks and the resulting cookies back as NDJSON,
and keeps nothing. Private/loopback/link-local/metadata ranges are refused
after DNS on every hop (an AddressFilter on the resolver plus a per-hop URL
check), with size caps, a timeout ceiling, a rate limit, host allow/deny
lists and an optional token.

The web host now sends through it: the wasm worker resolves and renders
the request (render_http_request moved into yaak-models so it builds for
wasm; re-exported from its old paths), the tab posts it, and stores what
comes back where the desktop stores it. Requests needing auth plugins or
template functions are refused with the reason until plugins run in the
browser.

crates/yaak-models/src/render.rs

@@ -1,5 +1,99 @@
-use crate::models::{Environment, EnvironmentVariable};
-use std::collections::HashMap;
+use crate::models::{
+    Environment, EnvironmentVariable, HttpRequest, HttpRequestHeader, HttpUrlParameter,
+};
+use crate::path_placeholders::apply_path_placeholders;
+use log::info;
+use serde_json::Value;
+use std::collections::{BTreeMap, HashMap};
+use yaak_templates::{RenderOptions, TemplateCallback, parse_and_render, render_json_value_raw};
+
+/// Render every template in a request against an environment chain.
+///
+/// Lives here rather than beside the send engine so that the browser's wasm
+/// host, which has the model layer but no sockets, renders exactly what the
+/// desktop renders.
+pub async fn render_http_request<T: TemplateCallback>(
+    request: &HttpRequest,
+    environment_chain: Vec<Environment>,
+    callback: &T,
+    options: &RenderOptions,
+) -> yaak_templates::error::Result<HttpRequest> {
+    let vars = &make_vars_hashmap(environment_chain);
+
+    let mut url_parameters = Vec::new();
+    for parameter in request.url_parameters.clone() {
+        if !parameter.enabled {
+            continue;
+        }
+
+        url_parameters.push(HttpUrlParameter {
+            enabled: parameter.enabled,
+            name: parse_and_render(parameter.name.as_str(), vars, callback, options).await?,
+            value: parse_and_render(parameter.value.as_str(), vars, callback, options).await?,
+            id: parameter.id,
+        })
+    }
+
+    let mut headers = Vec::new();
+    for header in request.headers.clone() {
+        if !header.enabled {
+            continue;
+        }
+
+        headers.push(HttpRequestHeader {
+            enabled: header.enabled,
+            name: parse_and_render(header.name.as_str(), vars, callback, options).await?,
+            value: parse_and_render(header.value.as_str(), vars, callback, options).await?,
+            id: header.id,
+        })
+    }
+
+    let mut body = BTreeMap::new();
+    for (key, value) in request.body.clone() {
+        let value = if key == "form" { strip_disabled_form_entries(value) } else { value };
+        body.insert(key, render_json_value_raw(value, vars, callback, options).await?);
+    }
+
+    let authentication = {
+        let mut disabled = false;
+        let mut auth = BTreeMap::new();
+
+        match request.authentication.get("disabled") {
+            Some(Value::Bool(true)) => {
+                disabled = true;
+            }
+            Some(Value::String(template)) => {
+                disabled = parse_and_render(template.as_str(), vars, callback, options)
+                    .await
+                    .unwrap_or_default()
+                    .is_empty();
+                info!(
+                    "Rendering authentication.disabled as a template: {disabled} from \"{template}\""
+                );
+            }
+            _ => {}
+        }
+
+        if disabled {
+            auth.insert("disabled".to_string(), Value::Bool(true));
+        } else {
+            for (key, value) in request.authentication.clone() {
+                if key == "disabled" {
+                    auth.insert(key, Value::Bool(false));
+                } else {
+                    auth.insert(key, render_json_value_raw(value, vars, callback, options).await?);
+                }
+            }
+        }
+
+        auth
+    };
+
+    let url = parse_and_render(request.url.clone().as_str(), vars, callback, options).await?;
+    let (url, url_parameters) = apply_path_placeholders(&url, &url_parameters);
+
+    Ok(HttpRequest { url, url_parameters, headers, body, authentication, ..request.to_owned() })
+}
 
 pub fn make_vars_hashmap(environment_chain: Vec<Environment>) -> HashMap<String, String> {
     let mut variables = HashMap::new();
@@ -27,3 +121,70 @@ fn add_variable_to_map(
 
     map
 }
+
+fn strip_disabled_form_entries(v: Value) -> Value {
+    match v {
+        Value::Array(items) => Value::Array(
+            items
+                .into_iter()
+                .filter(|item| item.get("enabled").and_then(|e| e.as_bool()).unwrap_or(true))
+                .collect(),
+        ),
+        v => v,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn test_strip_disabled_form_entries() {
+        let input = json!([
+            {"enabled": true, "name": "foo", "value": "bar"},
+            {"enabled": false, "name": "disabled", "value": "gone"},
+            {"enabled": true, "name": "baz", "value": "qux"},
+        ]);
+        let result = strip_disabled_form_entries(input);
+        assert_eq!(
+            result,
+            json!([
+                {"enabled": true, "name": "foo", "value": "bar"},
+                {"enabled": true, "name": "baz", "value": "qux"},
+            ])
+        );
+    }
+
+    #[test]
+    fn test_strip_disabled_form_entries_all_disabled() {
+        let input = json!([
+            {"enabled": false, "name": "a", "value": "b"},
+            {"enabled": false, "name": "c", "value": "d"},
+        ]);
+        let result = strip_disabled_form_entries(input);
+        assert_eq!(result, json!([]));
+    }
+
+    #[test]
+    fn test_strip_disabled_form_entries_missing_enabled_defaults_to_kept() {
+        let input = json!([
+            {"name": "no_enabled_field", "value": "kept"},
+            {"enabled": false, "name": "disabled", "value": "gone"},
+        ]);
+        let result = strip_disabled_form_entries(input);
+        assert_eq!(
+            result,
+            json!([
+                {"name": "no_enabled_field", "value": "kept"},
+            ])
+        );
+    }
+
+    #[test]
+    fn test_strip_disabled_form_entries_non_array_passthrough() {
+        let input = json!("just a string");
+        let result = strip_disabled_form_entries(input.clone());
+        assert_eq!(result, input);
+    }
+}