Reduce fmt usage in String() methods

fsthttp/imageopto/imageopto.go

@@ -57,13 +57,10 @@ func (a Auto) String() string { return string(a) }
 
 func fmtFloat(f float64) string {
 	nearest3 := math.Round(1000.0*f) / 1000.0
-	if _, fract := math.Modf(nearest3); fract > 0.0 {
-		return fmt.Sprintf("%v", nearest3)
-	}
-	return fmt.Sprintf("%v", int32(f))
+	return strconv.FormatFloat(nearest3, 'g', -1, 64)
 }
 
-// PixelsOrPercentage specifies a position along an exist.
+// PixelsOrPercentage specifies a length as either pixels or a percentage.
 //
 // Valid values are either an integer number of pixels, or a percentage followed by `p`.
 type PixelsOrPercentage string
@@ -158,9 +155,9 @@ func (area *Area) String() string {
 	case areaStateNone:
 		return ""
 	case areaStateAspectRatio:
-		return fmt.Sprintf("%v:%v", area.aspect.w, area.aspect.h)
+		return strconv.FormatUint(uint64(area.aspect.w), 10) + ":" + strconv.FormatUint(uint64(area.aspect.h), 10)
 	case areaStateWidthHeight:
-		return fmt.Sprintf("%v,%v", area.widthHeight.w, area.widthHeight.h)
+		return area.widthHeight.w.String() + "," + area.widthHeight.h.String()
 	}
 	return "error"
 }
@@ -256,7 +253,7 @@ type Sides struct {
 }
 
 func (s *Sides) String() string {
-	return fmt.Sprintf("%v,%v,%v,%v", s.Top, s.Right, s.Bottom, s.Left)
+	return s.Top.String() + "," + s.Right.String() + "," + s.Bottom.String() + "," + s.Left.String()
 }
 
 func (s *Sides) validate() error {
@@ -289,7 +286,7 @@ func (s *Sides) validate() error {
 type OptimizeLevel string
 
 const (
-	// OptimizeLevelLow means the output mage quality will be similar to the input image quality.
+	// OptimizeLevelLow means the output image quality will be similar to the input image quality.
 	OptimizeLevelLow OptimizeLevel = "low"
 
 	// OptimizeLevelMedium means more optimization is allowed, while attempting to preserve the visual
@@ -329,8 +326,10 @@ type HexColor struct {
 }
 
 func (h *HexColor) String() string {
-	return fmt.Sprintf("%v,%v,%v,%v", h.R, h.G, h.B, h.A)
-
+	return strconv.Itoa(int(h.R)) + "," +
+		strconv.Itoa(int(h.G)) + "," +
+		strconv.Itoa(int(h.B)) + "," +
+		strconv.FormatFloat(float64(h.A), 'g', -1, 32)
 }
 
 func (h *HexColor) validate() error {
@@ -441,9 +440,9 @@ func (b *BlurMode) String() string {
 	case blurModeStateNone:
 		return ""
 	case blurModeStatePercentage:
-		return fmt.Sprintf("%vp", b.percentage)
+		return strconv.FormatFloat(b.percentage, 'g', -1, 64) + "p"
 	case blurModeStatePixels:
-		return fmt.Sprintf("%v", b.pixels)
+		return strconv.FormatFloat(b.pixels, 'g', -1, 64)
 	}
 
 	return "error"
@@ -608,7 +607,9 @@ type Sharpen struct {
 }
 
 func (s *Sharpen) String() string {
-	return fmt.Sprintf("a%v,r%v,t%v", s.Amount, fmtFloat(float64(s.Radius)), s.Threshold)
+	return "a" + strconv.Itoa(int(s.Amount)) +
+		",r" + fmtFloat(float64(s.Radius)) +
+		",t" + strconv.Itoa(int(s.Threshold))
 }
 
 func (s *Sharpen) validate() error {
@@ -626,7 +627,7 @@ func (s *Sharpen) validate() error {
 type EnableOpt string
 
 const (
-	/// EnableOptUpsace allow images to be resized such that the output image's dimensions are
+	/// EnableOptUpscale allows images to be resized such that the output image's dimensions are
 	/// larger than the source image.
 	EnableOptUpscale EnableOpt = "upscale"
 )
@@ -889,7 +890,7 @@ func (o *Options) QueryString() (string, error) {
 	}
 
 	if o.Dpr != 0 {
-		args = append(args, "dpr="+fmt.Sprintf("%v", o.Dpr))
+		args = append(args, "dpr="+strconv.FormatFloat(float64(o.Dpr), 'g', -1, 32))
 	}
 
 	if o.Enable.isSet() {

fsthttp/imageopto/imageopto_test.go

@@ -199,6 +199,16 @@ func TestOpts(t *testing.T) {
 
 			"region=us_east&precrop=1:1,offset-x30,offset-y15,safe",
 		},
+
+		// fmtFloat: a value that rounds to a whole number must format as that
+		// whole number. Sharpen.Radius=1.9999 rounds to 2.0 -> "r2".
+		{
+			&Options{
+				Region:  RegionUsEast,
+				Sharpen: &Sharpen{Amount: 5, Radius: 1.9999, Threshold: 1},
+			},
+			"region=us_east&sharpen=a5,r2,t1",
+		},
 	}
 
 	for i, tt := range tests {