String values should pass their content-type correctly on http requests with a body (e.g. http post) (#13731)

# Description
The content-type was not being handled appropriately when sending
requests with a string value.

# User-Facing Changes
- Passing a string value through a pipeline with a content-type set as
metadata is handled correctly
- Passing a string value as a parameter with a content-type set as a
flag is handled correctly.

crates/nu-command/src/network/http/client.rs

@@ -7,6 +7,7 @@ use base64::{
 use multipart_rs::MultipartWriter;
 use nu_engine::command_prelude::*;
 use nu_protocol::{ByteStream, LabeledError, Signals};
+use serde_json::Value as JsonValue;
 use std::{
     collections::HashMap,
     io::Cursor,
@@ -257,24 +258,37 @@ fn send_json_request(
     span: Span,
     signals: &Signals,
 ) -> Result<Response, ShellErrorOrRequestError> {
-    let data = match body {
+    match body {
         Value::Int { .. } | Value::List { .. } | Value::Record { .. } => {
-            value_to_json_value(&body)?
+            let data = value_to_json_value(&body)?;
+            send_cancellable_request(request_url, Box::new(|| req.send_json(data)), span, signals)
         }
         // If the body type is string, assume it is string json content.
         // If parsing fails, just send the raw string
         Value::String { val: s, .. } => {
-            serde_json::from_str(&s).unwrap_or_else(|_| nu_json::Value::String(s))
+            if let Ok(jvalue) = serde_json::from_str::<JsonValue>(&s) {
+                send_cancellable_request(
+                    request_url,
+                    Box::new(|| req.send_json(jvalue)),
+                    span,
+                    signals,
+                )
+            } else {
+                let data = serde_json::from_str(&s).unwrap_or_else(|_| nu_json::Value::String(s));
+                send_cancellable_request(
+                    request_url,
+                    Box::new(|| req.send_json(data)),
+                    span,
+                    signals,
+                )
+            }
         }
-        _ => {
-            return Err(ShellErrorOrRequestError::ShellError(
-                ShellError::UnsupportedHttpBody {
-                    msg: format!("Accepted types: [Int, List, String, Record]. Check: {HTTP_DOCS}"),
-                },
-            ))
-        }
-    };
-    send_cancellable_request(request_url, Box::new(|| req.send_json(data)), span, signals)
+        _ => Err(ShellErrorOrRequestError::ShellError(
+            ShellError::UnsupportedHttpBody {
+                msg: format!("Accepted types: [Int, List, String, Record]. Check: {HTTP_DOCS}"),
+            },
+        )),
+    }
 }
 
 fn send_form_request(

crates/nu-command/src/network/http/patch.rs

@@ -126,7 +126,7 @@ impl Command for SubCommand {
             },
             Example {
                 description: "Patch JSON content from a pipeline to example.com",
-                example: "open foo.json | http patch https://www.example.com",
+                example: "open --raw foo.json | http patch https://www.example.com",
                 result: None,
             },
         ]

crates/nu-command/src/network/http/post.rs

@@ -124,7 +124,7 @@ impl Command for SubCommand {
             },
             Example {
                 description: "Post JSON content from a pipeline to example.com",
-                example: "open foo.json | http post https://www.example.com",
+                example: "open --raw foo.json | http post https://www.example.com",
                 result: None,
             },
             Example {

crates/nu-command/src/network/http/put.rs

@@ -124,7 +124,7 @@ impl Command for SubCommand {
             },
             Example {
                 description: "Put JSON content from a pipeline to example.com",
-                example: "open foo.json | http put https://www.example.com",
+                example: "open --raw foo.json | http put https://www.example.com",
                 result: None,
             },
         ]

crates/nu-command/tests/commands/network/http/post.rs

@@ -115,6 +115,24 @@ fn http_post_json_is_success() {
     assert!(actual.out.is_empty())
 }
 
+#[test]
+fn http_post_json_string_is_success() {
+    let mut server = Server::new();
+
+    let mock = server
+        .mock("POST", "/")
+        .match_body(r#"{"foo":"bar"}"#)
+        .create();
+
+    let actual = nu!(format!(
+        r#"http post -t 'application/json' {url} '{{"foo":"bar"}}'"#,
+        url = server.url()
+    ));
+
+    mock.assert();
+    assert!(actual.out.is_empty())
+}
+
 #[test]
 fn http_post_json_list_is_success() {
     let mut server = Server::new();
@@ -149,7 +167,7 @@ fn http_post_json_int_is_success() {
 }
 
 #[test]
-fn http_post_json_string_is_success() {
+fn http_post_json_raw_string_is_success() {
     let mut server = Server::new();
 
     let mock = server.mock("POST", "/").match_body(r#""test""#).create();