Fixes #286 - Add leading/trailing 0 to Float32 literals (#287)

* fix #286

Add leading/trailing 0 for Float32 literals, similar to how we do it for
other Float literals

* fmt

* doc

docs/src/transforms.md

@@ -63,6 +63,16 @@ a = .1
 a = 0.1
 ```
 
+For `Float32` if there is no decimal point, `.0` is added:
+
+```julia
+a = 1f0
+
+->
+
+a = 1.0f0
+```
+
 See [this issue](https://github.com/domluna/JuliaFormatter.jl/issues/66) for more details.
 
 ## Surround `where` arguments with curly brackets

src/styles/default/pretty.jl

@@ -366,12 +366,28 @@ end
     loc = cursor_loc(s)
     if !is_str_or_cmd(cst.kind)
         val = cst.val
-        if cst.kind === Tokens.FLOAT && cst.val[end] == '.'
-            # If a floating point ends in `.`, add trailing zero.
-            val *= '0'
-        elseif cst.kind === Tokens.FLOAT && cst.val[1] == '.'
-            val = '0' * val
+
+        if cst.kind === Tokens.FLOAT && endswith(cst.val, "f0")
+            # Float32
+            val = val[1:end-2]
+            dotidx = findlast(c -> c == '.', val)
+            if dotidx === nothing
+                val *= ".0"
+            elseif dotidx == length(val)
+                val *= '0'
+            elseif dotidx == 1
+                val = '0' * val
+            end
+            val *= "f0"
+        elseif cst.kind === Tokens.FLOAT
+            if endswith(cst.val, ".")
+                # If a floating point ends in `.`, add trailing zero.
+                val *= '0'
+            elseif startswith(cst.val, ".")
+                val = '0' * val
+            end
         end
+
         s.offset += cst.fullspan
         return FST(cst, loc[1], loc[1], val)
     end

test/issues.jl

@@ -568,4 +568,24 @@
         @test fmt(str_) == str
         @test fmt(str, whitespace_ops_in_indices = true) == str_
     end
+
+    @testset "issue 286 - Float32 leading/trailing zeros" begin
+        str_ = """
+        a = 3.f0
+        b = 3f0
+        c = 30f0
+        d = 30.0f0
+        e = 30.123f0
+        f = .123f0
+        """
+        str = """
+        a = 3.0f0
+        b = 3.0f0
+        c = 30.0f0
+        d = 30.0f0
+        e = 30.123f0
+        f = 0.123f0
+        """
+        @test fmt(str_) == str
+    end
 end