{"record":{"id":"29dc1a07b0af38cd","repo":"ducaale/xh","slug":"json-values-are-not-supported-in-multipart-fields","errorCode":null,"errorMessage":"JSON values are not supported in multipart fields","messagePattern":"JSON values are not supported in multipart fields","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/request_items.rs","lineNumber":366,"sourceCode":" text_fields.push((key, fs::read_to_string(path)?));\n }\n RequestItem::FormFile { .. } => unreachable!(),\n RequestItem::HttpHeader(..) => {}\n RequestItem::HttpHeaderFromFile(..) => {}\n RequestItem::HttpHeaderToUnset(..) => {}\n RequestItem::UrlParam(..) => {}\n RequestItem::UrlParamFromFile(..) => {}\n }\n }\n Ok(Body::Form(text_fields))\n }\n\n fn body_as_multipart(self) -> Result {\n let mut form = multipart::Form::new();\n for item in self.items {\n match item {\n RequestItem::JsonField(..) | RequestItem::JsonFieldFromFile(..) => {\n return Err(anyhow!(\"JSON values are not supported in multipart fields\"));\n }\n RequestItem::DataField { key, value, .. } => {\n form = form.text(key, value);\n }\n RequestItem::DataFieldFromFile { key, value, .. } => {\n let path = expand_tilde(value);\n form = form.text(key, fs::read_to_string(path)?);\n }\n RequestItem::FormFile {\n key,\n file_name,\n file_type,\n file_name_header,\n } => {\n let mut part = file_to_part(expand_tilde(file_name))?;\n if let Some(file_type) = file_type {\n part = part.mime_str(&file_type)?;\n }","sourceCodeStart":348,"sourceCodeEnd":384,"githubUrl":"https://github.com/ducaale/xh/blob/2404aceecc08b0b2d100fedc96f57745cd5904dc/src/request_items.rs#L348-L384","documentation":"Multipart bodies consist of named parts with text or binary content; raw JSON typed values from `key:=value` items have no multipart representation. `body_as_multipart` therefore rejects any `RequestItem::JsonField`/`JsonFieldFromFile` item with this error.","triggerScenarios":"Running `xh --multipart POST :8080 name=John count:=2` (or `--form` with multipart resolved), where a `:=` or `@file:=` item is present among the request items.","commonSituations":"Uploading files with `--multipart` while keeping JSON fields from an earlier JSON-mode command line; generated command lines that append `:=` items regardless of body mode.","solutions":["Convert `:=` items to plain `key=value` text fields when in multipart mode.","Remove `--multipart`/`--form` if you need typed JSON values in the body.","Send the JSON part separately, e.g. as a JSON string field: `json='{\"count\":2}'`."],"exampleFix":"// before\nxh --multipart POST :8080 file@photo.png count:=2\n// after\nxh --multipart POST :8080 file@photo.png count=2","handlingStrategy":"validation","validationCode":"# guard: multipart must not contain := items\nif echo \"$args\" | grep -q -- '--multipart' && echo \"$args\" | grep -q ':='; then\n echo 'JSON (:=) fields are invalid in multipart'; exit 1\nfi","typeGuard":null,"tryCatchPattern":"match result {\n Err(e) if e.to_string().contains(\"not supported in multipart\") => {\n eprintln!(\"convert := items to plain text fields for multipart\");\n }\n other => other?,\n}","preventionTips":["Use only key=value and key@file items with --multipart.","Send structured data as a JSON string field if needed.","Sanitize request-item lists before switching body modes."],"tags":["http","multipart","json","cli"],"backgroundTag":"incompatible-source-type","analyzedSha":"2404aceecc08b0b2d100fedc96f57745cd5904dc","analyzedAt":"2026-09-13T19:13:33.814Z","contentChangedAt":"2026-09-13T19:13:33.814Z","schemaVersion":2},"datasetVersion":"2026-09-16T09:17:16.951Z"}