fix: apply per-field Content-Type in multipart/form-data serialization

packages/bruno-cli/src/runner/prepare-request.js

@@ -8,6 +8,7 @@ const fs = require('node:fs');
 const { mergeHeaders, mergeScripts, mergeVars, mergeAuth, getTreePathFromCollectionToItem } = require('../utils/collection');
 const path = require('node:path');
 const { isLargeFile } = require('../utils/filesystem');
+const { createFormData } = require('../utils/form-data');
 const { getFormattedOauth2Credentials } = require('../utils/oauth2');
 
 const STREAMING_FILE_SIZE_THRESHOLD = 20 * 1024 * 1024; // 20MB
@@ -403,9 +404,10 @@ const prepareRequest = async (item = {}, collection = {}) => {
   }
 
   if (request.body.mode === 'multipartForm') {
-    axiosRequest.headers['content-type'] = 'multipart/form-data';
     const enabledParams = filter(request.body.multipartForm, (p) => p.enabled);
-    axiosRequest.data = enabledParams;
+    const form = createFormData(enabledParams, collectionPath, STREAMING_FILE_SIZE_THRESHOLD);
+    Object.assign(axiosRequest.headers, form.getHeaders());
+    axiosRequest.data = form;
   }
 
   if (request.body.mode === 'graphql') {

packages/bruno-cli/src/utils/form-data.js

@@ -2,8 +2,11 @@ const { forEach } = require('lodash');
 const FormData = require('form-data');
 const fs = require('fs');
 const path = require('path');
+const { isLargeFile } = require('./filesystem');
 
-const createFormData = (data, collectionPath) => {
+const STREAMING_FILE_SIZE_THRESHOLD = 20 * 1024 * 1024; // 20MB
+
+const createFormData = (data, collectionPath, streamThreshold = STREAMING_FILE_SIZE_THRESHOLD) => {
   // make axios work in node using form data
   // reference: https://github.com/axios/axios/issues/1006#issuecomment-320165427
   const form = new FormData();
@@ -13,25 +16,33 @@ const createFormData = (data, collectionPath) => {
     if (contentType) {
       options.contentType = contentType;
     }
-    if (type === 'text') {
-      if (Array.isArray(value)) {
-        value.forEach((val) => form.append(name, val, options));
-      } else {
-        form.append(name, value, options);
-      }
-      return;
-    }
-
     if (type === 'file') {
-      const filePaths = value || [];
+      const filePaths = Array.isArray(value) ? value : (value ? [value] : []);
       filePaths.forEach((filePath) => {
+        if (!filePath) return;
         let trimmedFilePath = filePath.trim();
         if (!path.isAbsolute(trimmedFilePath)) {
           trimmedFilePath = path.join(collectionPath, trimmedFilePath);
         }
         options.filename = path.basename(trimmedFilePath);
-        form.append(name, fs.createReadStream(trimmedFilePath), options);
+        try {
+          form.append(
+            name,
+            isLargeFile(trimmedFilePath, streamThreshold)
+              ? fs.createReadStream(trimmedFilePath)
+              : fs.readFileSync(trimmedFilePath),
+            options
+          );
+        } catch (error) {
+          console.error('Error reading file:', error);
+        }
       });
+    } else {
+      if (Array.isArray(value)) {
+        value.forEach((val) => form.append(name, val ?? '', options));
+      } else {
+        form.append(name, value ?? '', options);
+      }
     }
   });
   return form;

packages/bruno-cli/tests/utils/form-data.spec.js

@@ -0,0 +1,48 @@
+const { createFormData } = require('../../src/utils/form-data');
+const os = require('os');
+
+const collectionPath = os.tmpdir();
+
+describe('utils: createFormData', () => {
+  test('includes per-part Content-Type for text field with contentType', () => {
+    const data = [
+      {
+        name: 'message',
+        type: 'text',
+        value: '{"key":"val"}',
+        contentType: 'application/json; charset=utf-8'
+      }
+    ];
+    const form = createFormData(data, collectionPath);
+    const buffer = form.getBuffer().toString();
+    expect(buffer).toContain('Content-Type: application/json; charset=utf-8');
+  });
+
+  test('omits Content-Type header for text field without contentType', () => {
+    const data = [{ name: 'field', type: 'text', value: 'hello' }];
+    const form = createFormData(data, collectionPath);
+    const buffer = form.getBuffer().toString();
+    expect(buffer).toContain('name="field"');
+    expect(buffer).toContain('hello');
+    expect(buffer).not.toContain('Content-Type:');
+  });
+
+  test('appends multiple text values from an array as separate parts', () => {
+    const data = [{ name: 'tag', type: 'text', value: ['a', 'b'] }];
+    const form = createFormData(data, collectionPath);
+    const buffer = form.getBuffer().toString();
+    const matches = buffer.match(/name="tag"/g) || [];
+    expect(matches.length).toBe(2);
+  });
+
+  test('handles single-string file value (not wrapped in array)', () => {
+    const data = [{ name: 'file', type: 'file', value: 'nonexistent.txt' }];
+    const consoleSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+    try {
+      expect(() => createFormData(data, collectionPath)).not.toThrow();
+      expect(consoleSpy).toHaveBeenCalled();
+    } finally {
+      consoleSpy.mockRestore();
+    }
+  });
+});

packages/bruno-electron/src/ipc/network/prepare-request.js

@@ -5,6 +5,7 @@ const fs = require('node:fs');
 const { getTreePathFromCollectionToItem, mergeHeaders, mergeScripts, mergeVars, getFormattedCollectionOauth2Credentials, mergeAuth } = require('../../utils/collection');
 const path = require('node:path');
 const { isLargeFile } = require('../../utils/filesystem');
+const { createFormData } = require('../../utils/form-data');
 
 const STREAMING_FILE_SIZE_THRESHOLD = 20 * 1024 * 1024; // 20MB
 
@@ -473,11 +474,12 @@ const prepareRequest = async (item, collection = {}, abortController) => {
   }
 
   if (request.body.mode === 'multipartForm') {
-    if (!contentTypeDefined) {
-      axiosRequest.headers['content-type'] = 'multipart/form-data';
-    }
     const enabledParams = filter(request.body.multipartForm, (p) => p.enabled);
-    axiosRequest.data = enabledParams;
+    axiosRequest._originalMultipartData = enabledParams;
+    axiosRequest.collectionPath = collectionPath;
+    const form = createFormData(enabledParams, collectionPath, STREAMING_FILE_SIZE_THRESHOLD);
+    Object.assign(axiosRequest.headers, form.getHeaders());
+    axiosRequest.data = form;
   }
 
   if (request.body.mode === 'graphql') {

packages/bruno-electron/src/utils/form-data.js

@@ -2,6 +2,9 @@ const { forEach } = require('lodash');
 const FormData = require('form-data');
 const fs = require('fs');
 const path = require('path');
+const { isLargeFile } = require('./filesystem');
+
+const STREAMING_FILE_SIZE_THRESHOLD = 20 * 1024 * 1024; // 20MB
 
 const formatMultipartData = (multipartData, boundary) => {
   if (!Array.isArray(multipartData) || multipartData.length === 0) {
@@ -20,45 +23,39 @@ const formatMultipartData = (multipartData, boundary) => {
     return 'file';
   };
 
-  const formatValue = (value) => {
-    if (Array.isArray(value)) {
-      return value.map((v) => String(v ?? '')).join(', ');
-    }
-    return String(value ?? '');
-  };
-
   const boundaryValue = normalizeBoundary(boundary);
   const parts = [];
 
   multipartData.forEach((field) => {
     if (!field || !field.name) return;
 
-    parts.push(`----${boundaryValue}`);
-    parts.push('Content-Disposition: form-data');
-
     if (field.type === 'file') {
       const filePaths = Array.isArray(field.value) ? field.value : (field.value ? [field.value] : ['']);
       filePaths.forEach((filePath) => {
-        parts.push(`----${boundaryValue}`);
-        parts.push('Content-Disposition: form-data');
         const fileName = getFileName(filePath);
-        parts.push(`name: ${field.name}`);
+        parts.push(`----${boundaryValue}`);
+        parts.push(`Content-Disposition: form-data; name: ${field.name}; filename: ${fileName}`);
+        if (field.contentType) parts.push(`Content-Type: ${field.contentType}`);
         parts.push(`value: [File: ${fileName}]`);
         parts.push('');
       });
     } else {
-      const value = formatValue(field.value);
-      parts.push(`name: ${field.name}`);
-      parts.push(`value: ${value}`);
-      parts.push('');
+      const values = Array.isArray(field.value) ? field.value : [field.value ?? ''];
+      values.forEach((val) => {
+        parts.push(`----${boundaryValue}`);
+        parts.push(`Content-Disposition: form-data; name: ${field.name}`);
+        if (field.contentType) parts.push(`Content-Type: ${field.contentType}`);
+        parts.push(`value: ${String(val ?? '')}`);
+        parts.push('');
+      });
     }
   });
 
   parts.push(`----${boundaryValue}--`);
   return parts.join('\n');
 };
 
-const createFormData = (data, collectionPath) => {
+const createFormData = (data, collectionPath, streamThreshold = STREAMING_FILE_SIZE_THRESHOLD) => {
   // make axios work in node using form data
   // reference: https://github.com/axios/axios/issues/1006#issuecomment-320165427
   const form = new FormData();
@@ -68,25 +65,33 @@ const createFormData = (data, collectionPath) => {
     if (contentType) {
       options.contentType = contentType;
     }
-    if (type === 'text') {
-      if (Array.isArray(value)) {
-        value.forEach((val) => form.append(name, val, options));
-      } else {
-        form.append(name, value, options);
-      }
-      return;
-    }
-
     if (type === 'file') {
-      const filePaths = value || [];
+      const filePaths = Array.isArray(value) ? value : (value ? [value] : []);
       filePaths.forEach((filePath) => {
+        if (!filePath) return;
         let trimmedFilePath = filePath.trim();
         if (!path.isAbsolute(trimmedFilePath)) {
           trimmedFilePath = path.join(collectionPath, trimmedFilePath);
         }
         options.filename = path.basename(trimmedFilePath);
-        form.append(name, fs.createReadStream(trimmedFilePath), options);
+        try {
+          form.append(
+            name,
+            isLargeFile(trimmedFilePath, streamThreshold)
+              ? fs.createReadStream(trimmedFilePath)
+              : fs.readFileSync(trimmedFilePath),
+            options
+          );
+        } catch (error) {
+          console.error('Error reading file:', error);
+        }
       });
+    } else {
+      if (Array.isArray(value)) {
+        value.forEach((val) => form.append(name, val ?? '', options));
+      } else {
+        form.append(name, value ?? '', options);
+      }
     }
   });
   return form;

packages/bruno-electron/tests/utils/form-data.spec.js

@@ -17,6 +17,7 @@ describe('utils: formatMultipartData', () => {
     const result = formatMultipartData(data, 'boundary');
 
     expect(result).toContain('name: file');
+    expect(result).toContain('filename: Dumy.xml');
     expect(result).toContain('value: [File: Dumy.xml]');
   });
 
@@ -43,4 +44,45 @@ describe('utils: formatMultipartData', () => {
     expect(formatMultipartData(data, '--boundary')).toContain('----boundary');
     expect(formatMultipartData(data, 'boundary--')).toContain('----boundary');
   });
+
+  test('should include per-part Content-Type when contentType is set on text field', () => {
+    const data = [{ name: 'message', type: 'text', value: '{"k":"v"}', contentType: 'application/json; charset=utf-8' }];
+    const result = formatMultipartData(data, 'boundary');
+
+    expect(result).toContain('Content-Type: application/json; charset=utf-8');
+  });
+
+  test('should only include Content-Type for parts that define contentType', () => {
+    const data = [
+      { name: 'json', type: 'text', value: '{"k":"v"}', contentType: 'application/json; charset=utf-8' },
+      { name: 'plain', type: 'text', value: 'hello' }
+    ];
+    const result = formatMultipartData(data, 'boundary');
+
+    expect(result).toContain('name: json');
+    expect(result).toContain('name: plain');
+    expect(result).toContain('Content-Type: application/json; charset=utf-8');
+    const contentTypeMatches = result.match(/Content-Type:/g) || [];
+    expect(contentTypeMatches.length).toBe(1);
+  });
+
+  test('should render array text values as separate parts', () => {
+    const data = [{ name: 'tag', type: 'text', value: ['a', 'b'] }];
+    const result = formatMultipartData(data, 'boundary');
+
+    const matches = result.match(/name: tag/g) || [];
+    expect(matches.length).toBe(2);
+    expect(result).toContain('value: a');
+    expect(result).toContain('value: b');
+  });
+
+  test('should render each file as a separate part with filename in disposition', () => {
+    const data = [{ name: 'attach', type: 'file', value: ['a.jpg', 'b.jpg'] }];
+    const result = formatMultipartData(data, 'boundary');
+
+    expect(result).toContain('filename: a.jpg');
+    expect(result).toContain('filename: b.jpg');
+    const matches = result.match(/name: attach/g) || [];
+    expect(matches.length).toBe(2);
+  });
 });