fix(flet-cli): correct dependency parsing (#6332)

[td3447]

Fix #6332

Summary

Commit message

Closes issue: #6332

• Adds a space (' ') in front of dependencies in pyproject.toml that have version constraints starting with < or <=.
• Fixes the issue where flet build would give a The system cannot find the file specified. error.

Additional Details

• This prevents users from having to manually edit the pyproject.toml after adding dependencies with uv add. uv does not have a leading space before the < but with flet build a lack of leading space raises an error.
• The function looks for a <= or < and bypasses all others, if it has one from the list then it appends a space and adds that to the set.

Test Code

• Builds tested on the following.

flet build windows | linux | apk

Type of change

• Bug fix (non-breaking change which fixes an issue)

Summary by Sourcery

Bug Fixes:

• Ensure dependencies with < or <= version constraints are formatted with a leading space to avoid build failures when parsing pyproject.toml dependencies.

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[FeodorFitsner]

Thank you for your PR!

This only fixes project.dependencies. flet build / flet publish prefer tool.poetry.dependencies first, and get_poetry_dependencies() can still emit pkg<ver without normalization, so Poetry users may still hit the same issue. Can you fix that too please?

[td3447]

Updates

• Added compatibility with poetry
• Edited format_dependency_version() to include checks for < or <= and include a leading space.

Test Code

• Builds tested on the following.

poetry run flet build windows | apk

Tests

[tool.poetry.dependencies]
 ✅ chardet = "<=6"
 ✅ chardet = "<6"
 ✅ chardet = "   <     6  "

[td3447]

Updates

• Fixed an error where a < after a , was not recognized as a dependency.
• Added more checks to ensure a wider variety of typos are covered.
• Fixed an issue where using a * wouldn't correctly look for any version and raise an error.
• Fixed an issue where using a ! after a , would raise an error, since it was missing the required in front.
• Ensured the correct separators were added for all the types of requirements I could think of
• Added support for clearing whitespace from uv dependencies, in the same way used with the poetry dependencies.
• Tests were conducted on both poetry and uv, using flet build

---

Testing

Poetry

poetry run flet build windows | apk -v

pyproject.toml (Poetry)

Test Case

[tool.poetry.dependencies]
boto3 = "*       "
packaging = "   26.0    "
urllib3 = "   ^   2.6.0    "
setuptools = "  ~  82.0.0  "
certifi = "  >=  2026.1.4  "
chardet = " < 6 "
requests = " <= 2.32.4 "
pydantic = " >= 2.9.0 ,     <3.0.0   "
pillow = "  >  11.1.0,  <=  12.0.0  "
sqlalchemy = "  >=   1.4   ,  <=2.0"
pandas = " >=  2.3,  != 2.3.3  "
scipy = { version = "^ 1.16", optional = true }
uvicorn = { version = ">=  0.42.0", extras = ["standard"] }
pywin32 = { version = " >=  310", markers = "sys_platform == 'win32'" }
numpy = { git = "https://github.com/numpy/numpy.git", branch = "main" }

Standard case

[tool.poetry.dependencies]
boto3 = "*"
packaging = "26.0"
urllib3 = "^2.6.0"
setuptools = "~82.0.0"
certifi = ">=2026.1.4"
chardet = "<6"
requests = "<=2.32.4"
pydantic = ">=2.9.0,<3.0.0"
pillow = ">11.1.0,<=12.0.0"
sqlalchemy = ">=1.4,<=2.0"
pandas = ">=2.3,!=2.3.3"
scipy = { version = "^1.16", optional = true }
uvicorn = { version = ">=0.42.0", extras = ["standard"] }
pywin32 = { version = ">=310", markers = "sys_platform == 'win32'" }
numpy = { git = "https://github.com/numpy/numpy.git", branch = "main" }

Output

[dependencies]
pandas>=2.3, !=2.3.3
boto3
certifi>=2026.1.4
chardet <6
pydantic>=2.9.0, <3.0.0
packaging==26.0
scipy>=1.16
requests <=2.32.4
numpy@git+https://github.com/numpy/numpy.git@main
pywin32>=310;sys_platform == 'win32'
setuptools~=82.0.0
pillow>11.1.0, <=12.0.0
urllib3>=2.6.0
uvicorn>=0.42.0
sqlalchemy>=1.4, <=2.0

Detailed Output

dep: boto3
sep: ''
val:
suf:

dep: packaging
sep: '=='
val: 26.0
suf:

dep: urllib3
sep: '>='
val: 2.6.0
suf:

dep: setuptools
sep: ''
val: ~=82.0.0
suf:

dep: certifi
sep: ''
val: >=2026.1.4
suf:

dep: chardet
sep: ''
val:  <6
suf:

dep: requests
sep: ''
val:  <=2.32.4
suf:

dep: pydantic
sep: ''
val: >=2.9.0, <3.0.0
suf:

dep: pillow
sep: ''
val: >11.1.0, <=12.0.0
suf:

dep: sqlalchemy
sep: ''
val: >=1.4, <=2.0
suf:

dep: pandas
sep: ''
val: >=2.3, !=2.3.3
suf:

start: scipy^1.16
dep: scipy
sep: '>='
val: 1.16
suf:

start: uvicorn>=0.42.0
dep: uvicorn
sep: ''
val: >=0.42.0
suf:

start: pywin32>=310
dep: pywin32
sep: ''
val: >=310
suf: ;sys_platform == 'win32'

dep: numpy
sep: '@'
val: git+https://github.com/numpy/numpy.git@main
suf:

Result

Build successful 🥳

---

UV

uv run flet build windows | apk -v

pyproject.toml (UV)

Test Case

dependencies = [
    "flet    ",
    "  boto3  ",
    "  packaging  ==   26.0    ",
    " urllib3  >=  2.6.0 ",
    "  setuptools  ~=  82.0.0 ",
    " certifi  >= 2026.1.4  ",
    "chardet <  6  ",
    "requests <=  2.32.4",
    "pydantic>=   2.9.0  , <3.0.0  ",
    "pillow>  11.1.0, <=12.0.0  ",
    "sqlalchemy>=1.4, <=2.0",
    "uvicorn[  standard  ]>=  0.42.0",
    "pywin32   >=310 ; sys_platform     == 'win32'",
    "numpy @ git+https://github.com/numpy/numpy.git@main",
]

Standard case

dependencies = [
    "flet",
    "boto3",
    "packaging==26.0",
    "urllib3>=2.6.0",
    "setuptools~=82.0.0",
    "certifi>=2026.1.4",
    "chardet <6",
    "requests<=2.32.4",
    "pydantic>=2.9.0, <3.0.0",
    "pillow>11.1.0, <=12.0.0",
    "sqlalchemy>=1.4, <=2.0",
    "pandas>=2.3, !=2.3.3",
    # "scipy>=1.16",
    "uvicorn[standard]>=0.42.0",
    "pywin32>=310; sys_platform == 'win32'",
    "numpy @ git+https://github.com/numpy/numpy.git@main",
]

Output

packaging==26.0
urllib3>=2.6.0
chardet <6
sqlalchemy>=1.4, <=2.0
pydantic>=2.9.0, <3.0.0
pillow>11.1.0, <=12.0.0
boto3
flet
pandas>=2.3, !=2.3.3
pywin32>=310;sys_platform=='win32'
requests <=2.32.4
uvicorn[standard]>=0.42.0
numpy@git+https://github.com/numpy/numpy.git@main
certifi>=2026.1.4
setuptools~=82.0.0

Detailed Output

dep: flet

dep: boto3

dep: packaging==26.0

dep: urllib3>=2.6.0

dep: setuptools~=82.0.0

dep: certifi>=2026.1.4

dep: chardet<6
val: chardet
sep: '<'
suf: 6

dep: requests<=2.32.4
val: requests
sep: '<='
suf: 2.32.4

dep: pydantic>=2.9.0,<3.0.0
val: pydantic>=2.9.0,
sep: '<'
suf: 3.0.0

dep: pillow>11.1.0,<=12.0.0
val: pillow>11.1.0,
sep: '<='
suf: 12.0.0

dep: sqlalchemy>=1.4,<=2.0
val: sqlalchemy>=1.4,
sep: '<='
suf: 2.0

dep: pandas>=2.3,!=2.3.3
val: pandas>=2.3,
sep: '!'
suf: =2.3.3

dep: uvicorn[standard]>=0.42.0

dep: pywin32>=310;sys_platform=='win32'

dep: numpy@git+https://github.com/numpy/numpy.git@main

Result

Build successful 🥳