[Python] Use Fantomas formatting and check CI

.config/dotnet-tools.json

@@ -0,0 +1,12 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "fantomas-tool": {
+      "version": "4.6.0",
+      "commands": [
+        "fantomas"
+      ]
+    }
+  }
+}

.editorconfig

@@ -7,3 +7,12 @@ indent_style = space
 # TS files
 [*.ts]
 indent_size = 2
+
+# Fantomas (see https://github.com/fsprojects/fantomas/blob/master/docs/Documentation.md)
+[*.fs]
+indent_size=4
+max_line_length=140
+fsharp_space_before_uppercase_invocation=false
+fsharp_space_before_member=false
+fsharp_space_around_delimiter=true
+fsharp_multiline_block_brackets_on_same_column=false

.github/workflows/test.yml

@@ -39,6 +39,12 @@ jobs:
         with:
           dotnet-version: '6.0.x'
 
+      - name: Setup dotnet tools
+        run: dotnet tool restore
+
+      - name: Check formatting
+        run: dotnet fantomas src/Fable.Transforms/Python -check
+
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
         with:

src/Fable.Transforms/Python/Prelude.fs

@@ -8,23 +8,34 @@ module Naming =
     open System.Text.RegularExpressions
 
     let lowerFirst (s: string) =
-        s.Substring(0,1).ToLowerInvariant() + s.Substring(1)
+        s.Substring(0, 1).ToLowerInvariant()
+        + s.Substring(1)
 
     let upperFirst (s: string) =
-        s.Substring(0,1).ToUpperInvariant() + s.Substring(1)
+        s.Substring(0, 1).ToUpperInvariant()
+        + s.Substring(1)
 
     let private dashify (separator: string) (input: string) =
-        Regex.Replace(input, "[a-z]?[A-Z]", fun m ->
-            if m.Value.Length = 1 then m.Value.ToLowerInvariant()
-            else m.Value.Substring(0,1) + separator + m.Value.Substring(1,1).ToLowerInvariant())
+        Regex.Replace(
+            input,
+            "[a-z]?[A-Z]",
+            fun m ->
+                if m.Value.Length = 1 then
+                    m.Value.ToLowerInvariant()
+                else
+                    m.Value.Substring(0, 1)
+                    + separator
+                    + m.Value.Substring(1, 1).ToLowerInvariant()
+        )
 
     let applyCaseRule caseRule name =
         match caseRule with
         | CaseRules.LowerFirst -> lowerFirst name
         | CaseRules.SnakeCase -> dashify "_" name
         | CaseRules.SnakeCaseAllCaps -> (dashify "_" name).ToUpperInvariant()
         | CaseRules.KebabCase -> dashify "-" name
-        | CaseRules.None | _ -> name
+        | CaseRules.None
+        | _ -> name
 
     let toSnakeCase (name: string) =
         if name.Length > 0 && Char.IsLower(name.[0]) then
@@ -33,8 +44,10 @@ module Naming =
             name
 
     let cleanNameAsPyIdentifier (name: string) =
-        if name = ".ctor" then "_ctor"
-        else name.Replace('.','_').Replace('`','_')
+        if name = ".ctor" then
+            "_ctor"
+        else
+            name.Replace('.', '_').Replace('`', '_')
 
     let pyKeywords =
         // https://docs.python.org/3/reference/lexical_analysis.html#keywords
@@ -103,57 +116,90 @@ module Naming =
             // Other names
             "self"
         ]
+
     let reflectionSuffix = "_reflection"
 
 
     let preventConflicts conflicts originalName =
         let rec check originalName n =
-            let name = if n > 0 then originalName + "_" + (string n) else originalName
-            if not (conflicts name) then name else check originalName (n+1)
+            let name =
+                if n > 0 then
+                    originalName + "_" + (string n)
+                else
+                    originalName
+
+            if not (conflicts name) then
+                name
+            else
+                check originalName (n + 1)
+
         check originalName 0
 
     let isIdentChar index (c: char) =
         let code = int c
+
         c = '_'
-        || (65 <= code && code <= 90)   // a-z
-        || (97 <= code && code <= 122)  // A-Z
+        || (65 <= code && code <= 90) // a-z
+        || (97 <= code && code <= 122) // A-Z
         // Digits are not allowed in first position, see #1397
         || (index > 0 && 48 <= code && code <= 57) // 0-9
 
     let hasIdentForbiddenChars (ident: string) =
         let mutable found = false
+
         for i = 0 to ident.Length - 1 do
-            found <- found || not(isIdentChar i ident.[i])
+            found <- found || not (isIdentChar i ident.[i])
+
         found
 
     let sanitizeIdentForbiddenChars (ident: string) =
         if hasIdentForbiddenChars ident then
-            System.String.Concat(seq {
-                for i = 0 to (ident.Length - 1) do
-                    let c = ident.[i]
-                    if isIdentChar i c
-                    then string c
-                    elif c = '$' || c = '_' || c = ' ' || c = '*' || c = '.'
-                    then "_"
-                    else "_" + System.String.Format("{0:X}", int c).PadLeft(4, '0')
-                })
-        else ident
+            System.String.Concat(
+                seq {
+                    for i = 0 to (ident.Length - 1) do
+                        let c = ident.[i]
+
+                        if isIdentChar i c then
+                            string c
+                        elif c = '$'
+                             || c = '_'
+                             || c = ' '
+                             || c = '*'
+                             || c = '.' then
+                            "_"
+                        else
+                            "_"
+                            + System
+                                .String
+                                .Format("{0:X}", int c)
+                                .PadLeft(4, '0')
+                }
+            )
+        else
+            ident
 
     let checkPyKeywords name =
-        if pyKeywords.Contains name
-        then name + "_"
-        else name
+        if pyKeywords.Contains name then
+            name + "_"
+        else
+            name
 
     let private printPart sanitize separator part overloadSuffix =
-        (if part = "" then "" else separator + (sanitize part)) +
-            (if overloadSuffix = "" then "" else "_" + overloadSuffix)
+        (if part = "" then
+             ""
+         else
+             separator + (sanitize part))
+        + (if overloadSuffix = "" then
+               ""
+           else
+               "_" + overloadSuffix)
 
     let private buildName sanitize name part =
-        (sanitize name) +
-            (match part with
-                | Naming.InstanceMemberPart(s, i) -> printPart sanitize "__" s i
-                | Naming.StaticMemberPart(s, i) -> printPart sanitize "_" s i
-                | Naming.NoMemberPart -> "")
+        (sanitize name)
+        + (match part with
+           | Naming.InstanceMemberPart (s, i) -> printPart sanitize "__" s i
+           | Naming.StaticMemberPart (s, i) -> printPart sanitize "_" s i
+           | Naming.NoMemberPart -> "")
 
     let sanitizeIdent conflicts name part =
         // Replace Forbidden Chars