Difference in behavior between signature and implementation files for single case DU

[nojaf]

Issue created from fantomas-online

Code

namespace foo

type SynTypeConstraint =

    /// F# syntax: is 'typar: struct
    | WhereTyparIsValueType of
        typar: SynTypar *
        range: range

Result

namespace foo


/// F# syntax: is 'typar: struct
type SynTypeConstraint = WhereTyparIsValueType of typar: SynTypar * range: range

Problem description

In an implementation file this is formatted as:

namespace foo

type SynTypeConstraint =

    /// F# syntax: is 'typar: struct
    | WhereTyparIsValueType of typar: SynTypar * range: range

Probably related to change in #948

Extra information

• The formatted result breaks by code.
• The formatted result gives compiler warnings.
• I or my company would be willing to help fix this.

Options

Fantomas Master at 7/16/2020

Name	Value
IndentSize	4
MaxLineLength	120
SemicolonAtEndOfLine	false
SpaceBeforeParameter	true
SpaceBeforeLowercaseInvocation	true
SpaceBeforeUppercaseInvocation	false
SpaceBeforeClassConstructor	false
SpaceBeforeMember	false
SpaceBeforeColon	false
SpaceAfterComma	true
SpaceBeforeSemicolon	false
SpaceAfterSemicolon	true
IndentOnTryWith	false
SpaceAroundDelimiter	true
MaxIfThenElseShortWidth	40
MaxInfixOperatorExpression	50
MaxRecordWidth	40
MaxArrayOrListWidth	40
MaxValueBindingWidth	40
MaxFunctionBindingWidth	40
MultilineBlockBracketsOnSameColumn	false
NewlineBetweenTypeDefinitionAndMembers	false
KeepIfThenInSameLine	false
MaxElmishWidth	40
SingleArgumentWebMode	false
AlignFunctionSignatureToIndentation	false
AlternativeLongMemberDefinitions	false
StrictMode	false

[nojaf]

No longer an issue.
See https://fsprojects.github.io/fantomas-tools/#/fantomas/preview?data=N4KABGBEDGD2AmBTSAuKA7AhgW0QZwAdNpEwAzWWAHQCcr1b6AXATwNIGUX0AVNxAMKx0eJjUwBLdEzABeRgzroIEAPTqwAMQDEYPNyaYAHmgl4wAclZEaaUTQCu0JgpVgAPmADqAC0Q1EPhsASTwANUwAGwdA-jBYMlc3FWtMWzAuXjY0sAAqJOSwcXQAc0Q0YrLIABpwKDxEJiYpErxUMABtOohQQsgAEmtkNEgpJhrulQGANyiY9q7CiAAGWqWoYPQkaQ4JAC9kNaWAFkmIAF1JgF8jnrOoQf520ekJvv7Z6OHO%2B4gARluyUgAFljAAZKSIMGIUpMHxvJZ-ABMy3ulzcN0mvSBj3YzwARpRIgi3DM5t9FkskYDSRxENgJHBIsIAIJMACiWwA8mQIehDr9yFEGmjroDsaTcd9IITYMSaQ9PvM0JTCgBmBUQSAcIgkABCiAoAQACmkcI1-CTkmIYqKMeL7gMhgSiVatR9yQtBcdNVAdcREAajVDYAB3fzQTANTbTWCR5rCN0pRyIO0qTFuCVTKUuuVJslfL3rACsvu1usDhtgAQAqgR2DRI9H0LH4xJE76yMLU4V0emHe9nSNZfLHR7CyrBQA2Mv%2B-VVgICSJRvBCEQ25zVpMQLuREW9sVYsdDqAj-Pj5U-dYAdlnFaD1cQwPp%2BMtne7aYgGZUWfdJ5lroKgWl6qskAAcd4Bg%2Bi5yh2gq7vuyR9l%2BA44v%2BZ5AReFKCgAnJBJAsmQTD%2BEI2DYJg25gDaPZIYembHk8w6AWOSrYesfyrIK5ZQQuiB0gyTJwesCE0W4yFgN%2BdyDoxp7Me8rFFoiAJcXOiCEcRND8YysHoJR1GfhJqGSuhck4gpk7sdSXGbNsTBcrwNAsF4EhwpRIkGZJYC-g8Jl5ph5lXoiGoqRWLI0LADhbAAIogkQSAyGl6SmHlGdm-5jOeAWgW4fw%2BlxoJGMEZA8H46DsnufE%2BNWTDOfArm%2BscqIHvaR7SXiIwZf5noWYipb5cYmxkBIRhcg2mBMNW7JGAQAR4Hg7a6b6xZNbRLX0W10qdSx3WBYUfwzv1RgAEqIHANDwLV9XeitYl0T%2BDHtVAW3yTt2UqH8t6HSdZ3wAAcg42CvjQPLBMR2BtL6fwpa1aEyZA2AOJEzRxfymjVuRTT%2BEEAovROu3JH8EFcd91bwMCiPI5CaM0BjiVltAPhms4-gAPqhhIdXwtD62w49LzjF1eNvf8eGHWF4gsFyNAQqIl3wg1N0qOJnneU6cPPWZr2CiiZYFeLmCS9LZhMP9gP%2BCDYMQ4KUPNf2MPGXDCNIxIKOINTtNY08gsgdrynrJA%2BuGzLTDk87rvu%2BNdNcQzTMaWzHOudz90bc8GuSll2tWf7BURF8epSPALRy5RjVJ1JvOba83tsVSwXZ8YmiRc4C351sRcJ-L11l15D2VwL21C9reX10YUWwEwADijRTTN%2BDzcIxdLYrFx3eXDt8xhA8%2B%2BsSJ9dnFMu5CerMtAADWeriGfjR4PZHDmkI0TYIt8EfrbKH22lcOb7j29Ugd-u-UQKGV2BomDhhhNjGKQ10AuQWiyLYz4zY0CtsJV%2Bq07Y83XtKb%2BmtB470%2Bv7AA0ogRABAiolRhJsO%2BuA%2BQ4yWO5N%2BhkP5-nVlXLeNdChIiJiPcqDI8A%2BEXl3RhKte65lHD-DhyQkSi39rsUokQ1I0BKADGENVED4mBAgOhhQGHoPfpgz%2BG9TLpy1usNUnF-YsjiiUdAjd0DN2ELsGx40HABB4LAGyqjxoLTcmg26a1k4VzEZlUxSw1R%2ByWAHJG-gsDNGmCGUoiCgZQKkLA4QKD6F%2BKVqvHuKcmJ%2BXYYpdUWdImh2aLQsEOB8TwEwEuWA81SiAOAZCXxFVu6qxzPk8RuDf7qjrpEqKZhMD4gUbwswPhMiGCMK0xC-iMGBKwc8GE8AeS0I4KwBRIS8FhOHpEzkKzeQtPpjQSIZBIDtNEV0rZvTkhqj3pE4hpDPHSE2BfTA9jO6oLacI1KLCjEFIkUU25-9InH3eafWheAwoRS2IA0QiAyYH1djPWa88RBJVtD85hPkv7GOzBnMxBDQVpGgogQZeBoA0HilIcaCKawwOEDFaAy5xAJmfl82Z2SAlr0MdgvF7oCVhO4ZE9ZVLnCaKQDM0SXL0x1HOEcUYeBNDzXaPpK4QA