fix: normalize malformed Bash tool arguments from OpenAI-compatible providers (#385)

* fix: normalize malformed Bash tool arguments from OpenAI-compatible providers

* fix: keep invalid Bash tool args from becoming commands

* fix: preserve malformed Bash JSON literals

* test: stabilize rebased PR 385 checks

* test: isolate provider profile env assertions

* fix: extend tool argument normalization to all tools and harden edge cases

- Extend STRING_ARGUMENT_TOOL_FIELDS to normalize Read, Write, Edit,
  Glob, and Grep plain-string arguments (fixes "Invalid tool parameters"
  errors reported by VennDev)
- Normalize streaming Bash args regardless of finish_reason, not only
  when finish_reason is 'tool_calls'
- Broaden isLikelyStructuredObjectLiteral to catch malformed object-shaped
  strings like {command:"pwd"} and {'command':'pwd'} (fixes CR2 from
  Vasanthdev2004)
- Apply blank/object-literal guard to all tools, not just Bash
- Extract duplicated JSON repair suffix combinations into shared constant
- Add 32 isolated unit tests for toolArgumentNormalization

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: skip streaming normalization on finish_reason length

Truncated tool calls (finish_reason: 'length') now preserve the raw
buffer instead of normalizing into executable commands, preventing
incomplete commands from becoming runnable.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: comprehensive tool argument normalization hardening

- Remove all { raw: ... } returns that caused InputValidationError with
  z.strictObject schemas — return {} instead for clean Zod errors
- Extend normalizeAtStop buffering to all mapped tools (Read, Write,
  Edit, Glob, Grep) so streaming paths also get normalized
- Make repairPossiblyTruncatedObjectJson generic — repair any valid
  JSON object, not just ones with a command field
- Export hasToolFieldMapping for streaming normalizeAtStop decision
- Skip normalization on finish_reason: length to preserve raw truncated
  buffer
- Update all test expectations to match new behavior

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/services/api/toolArgumentNormalization.test.ts

@@ -0,0 +1,180 @@
+import { describe, expect, test } from 'bun:test'
+import { normalizeToolArguments } from './toolArgumentNormalization'
+
+describe('normalizeToolArguments', () => {
+  describe('Bash tool', () => {
+    test('wraps plain string into { command }', () => {
+      expect(normalizeToolArguments('Bash', 'pwd')).toEqual({ command: 'pwd' })
+    })
+
+    test('wraps multi-word command', () => {
+      expect(normalizeToolArguments('Bash', 'ls -la /tmp')).toEqual({
+        command: 'ls -la /tmp',
+      })
+    })
+
+    test('passes through structured JSON object', () => {
+      expect(
+        normalizeToolArguments('Bash', '{"command":"echo hi"}'),
+      ).toEqual({ command: 'echo hi' })
+    })
+
+    test('returns empty object for blank string', () => {
+      expect(normalizeToolArguments('Bash', '')).toEqual({})
+      expect(normalizeToolArguments('Bash', '   ')).toEqual({})
+    })
+
+    test('returns parsed blank for JSON-encoded blank string', () => {
+      expect(normalizeToolArguments('Bash', '""')).toEqual('')
+      expect(normalizeToolArguments('Bash', '"  "')).toEqual('  ')
+    })
+
+    test('returns empty object for malformed structured object literal', () => {
+      expect(normalizeToolArguments('Bash', '{ "command": "pwd"')).toEqual({})
+    })
+
+    test.each([
+      ['{command:"pwd"}'],
+      ["{'command':'pwd'}"],
+      ['{command: pwd}'],
+    ])(
+      'returns empty object for malformed object-shaped string %s (does not wrap into command)',
+      (input) => {
+        expect(normalizeToolArguments('Bash', input)).toEqual({})
+      },
+    )
+
+    test.each([
+      ['false', false],
+      ['null', null],
+      ['[]', [] as unknown[]],
+      ['0', 0],
+      ['true', true],
+      ['123', 123],
+    ])(
+      'preserves JSON literal %s as-is (does not wrap into command)',
+      (input, expected) => {
+        expect(normalizeToolArguments('Bash', input)).toEqual(expected)
+      },
+    )
+
+    test('wraps JSON-encoded string into { command }', () => {
+      expect(normalizeToolArguments('Bash', '"pwd"')).toEqual({
+        command: 'pwd',
+      })
+    })
+  })
+
+  describe('undefined arguments', () => {
+    test('returns empty object for undefined', () => {
+      expect(normalizeToolArguments('Bash', undefined)).toEqual({})
+      expect(normalizeToolArguments('UnknownTool', undefined)).toEqual({})
+    })
+  })
+
+  describe('Read tool', () => {
+    test('wraps plain string into { file_path }', () => {
+      expect(normalizeToolArguments('Read', '/home/user/file.txt')).toEqual({
+        file_path: '/home/user/file.txt',
+      })
+    })
+
+    test('wraps JSON-encoded string into { file_path }', () => {
+      expect(normalizeToolArguments('Read', '"/home/user/file.txt"')).toEqual({
+        file_path: '/home/user/file.txt',
+      })
+    })
+
+    test('passes through structured JSON object', () => {
+      expect(
+        normalizeToolArguments('Read', '{"file_path":"/tmp/f.txt","limit":10}'),
+      ).toEqual({ file_path: '/tmp/f.txt', limit: 10 })
+    })
+  })
+
+  describe('Write tool', () => {
+    test('wraps plain string into { file_path }', () => {
+      expect(normalizeToolArguments('Write', '/tmp/out.txt')).toEqual({
+        file_path: '/tmp/out.txt',
+      })
+    })
+
+    test('passes through structured JSON object', () => {
+      expect(
+        normalizeToolArguments(
+          'Write',
+          '{"file_path":"/tmp/out.txt","content":"hello"}',
+        ),
+      ).toEqual({ file_path: '/tmp/out.txt', content: 'hello' })
+    })
+  })
+
+  describe('Edit tool', () => {
+    test('wraps plain string into { file_path }', () => {
+      expect(normalizeToolArguments('Edit', '/tmp/edit.ts')).toEqual({
+        file_path: '/tmp/edit.ts',
+      })
+    })
+
+    test('passes through structured JSON object', () => {
+      expect(
+        normalizeToolArguments(
+          'Edit',
+          '{"file_path":"/tmp/f.ts","old_string":"a","new_string":"b"}',
+        ),
+      ).toEqual({ file_path: '/tmp/f.ts', old_string: 'a', new_string: 'b' })
+    })
+  })
+
+  describe('Glob tool', () => {
+    test('wraps plain string into { pattern }', () => {
+      expect(normalizeToolArguments('Glob', '**/*.ts')).toEqual({
+        pattern: '**/*.ts',
+      })
+    })
+
+    test('passes through structured JSON object', () => {
+      expect(
+        normalizeToolArguments('Glob', '{"pattern":"*.js","path":"/src"}'),
+      ).toEqual({ pattern: '*.js', path: '/src' })
+    })
+  })
+
+  describe('Grep tool', () => {
+    test('wraps plain string into { pattern }', () => {
+      expect(normalizeToolArguments('Grep', 'TODO')).toEqual({
+        pattern: 'TODO',
+      })
+    })
+
+    test('passes through structured JSON object', () => {
+      expect(
+        normalizeToolArguments('Grep', '{"pattern":"fixme","path":"/src"}'),
+      ).toEqual({ pattern: 'fixme', path: '/src' })
+    })
+  })
+
+  describe('unknown tools', () => {
+    test('returns empty object for plain string (no known field mapping)', () => {
+      expect(normalizeToolArguments('UnknownTool', 'some value')).toEqual({})
+    })
+
+    test('passes through structured JSON object', () => {
+      expect(
+        normalizeToolArguments('UnknownTool', '{"key":"val"}'),
+      ).toEqual({ key: 'val' })
+    })
+
+    test('preserves JSON literals as-is', () => {
+      expect(normalizeToolArguments('UnknownTool', 'false')).toEqual(false)
+      expect(normalizeToolArguments('UnknownTool', 'null')).toEqual(null)
+      expect(normalizeToolArguments('UnknownTool', '[]')).toEqual([])
+    })
+
+    test('returns parsed string for JSON-encoded string on unknown tools', () => {
+      expect(normalizeToolArguments('UnknownTool', '"hello"')).toEqual(
+        'hello',
+      )
+    })
+  })
+})