feat: add inline background color syntax

docs/docs/configuration.md

@@ -200,8 +200,8 @@ segment's configuration will not render it when in that location. The engine wil
 
 #### Colors
 
-You have the ability to override the foreground color for text in any property that accepts it. The syntax is custom but
+You have the ability to override the foreground and/or background color for text in any property that accepts it. The syntax is custom but
-should be rather straighforward: `<#ffffff>this is white</> <#FF479C>but this is pink</>`. Anything between the color start
+should be rather straighforward: `<#ffffff,#000000>this is white with black background</> <#FF479C>but this is pink</>`. Anything between the color start
 `<#FF479C>` and end `</>` will be colored accordingly.
 
 For example, if you want `prefix` to print a colored bracket which isn't the same as the segment's `foreground`, you can
@@ -211,6 +211,18 @@ do so like this:
 "prefix": "<#CB4B16>┏[</>",
 ```
 
+If you also wanted to change the background color in the previous command, you would do so like this:
+
+```json
+"prefix": "<#CB4B16,#FFFFFF>┏[</>",
+```
+
+To change *only* the background color, just omit the first color from the above string:
+
+```json
+"prefix": "<,#FFFFFF>┏[</>",
+```
+
 Oh my Posh mainly supports three different color types being
 * Typical [hex colors][hexcolors] (for example `#CB4B16`).
 

renderer.go

@@ -146,19 +146,32 @@ func (r *Renderer) writeAndRemoveText(background, foreground, text, textToRemove
 }
 
 func (r *Renderer) write(background, foreground, text string) {
-	// first we match for any potentially valid color enclosed in <>
+	// first we match for any potentially valid colors enclosed in <>
-	rex := regexp.MustCompile(`<([#A-Za-z0-9]+)>(.*?)<\/>`)
+	rex := regexp.MustCompile(`<([#A-Za-z0-9]+)?(?:,([#A-Za-z0-9]+))?>(.*?)<\/>`)
 	match := rex.FindAllStringSubmatch(text, -1)
 	for i := range match {
-		extractedColor := match[i][1]
+		extractedForegroundColor := match[i][1]
-		if col := r.getAnsiFromColorString(extractedColor, false); col == "" && extractedColor != Transparent {
+		extractedBackgroundColor := match[i][2]
+		if col := r.getAnsiFromColorString(extractedForegroundColor, false); col == "" && extractedForegroundColor != Transparent && len(extractedBackgroundColor) == 0 {
 			continue // we skip invalid colors
 		}
+		if col := r.getAnsiFromColorString(extractedBackgroundColor, false); col == "" && extractedBackgroundColor != Transparent && len(extractedForegroundColor) == 0 {
+			continue // we skip invalid colors
+		}
+
+		// reuse function colors if only one was specified
+		if len(extractedBackgroundColor) == 0 {
+			extractedBackgroundColor = background
+		}
+		if len(extractedForegroundColor) == 0 {
+			extractedForegroundColor = foreground
+		}
+
 		escapedTextSegment := match[i][0]
-		innerText := match[i][2]
+		innerText := match[i][3]
 		textBeforeColorOverride := strings.Split(text, escapedTextSegment)[0]
 		text = r.writeAndRemoveText(background, foreground, textBeforeColorOverride, textBeforeColorOverride, text)
-		text = r.writeAndRemoveText(background, extractedColor, innerText, escapedTextSegment, text)
+		text = r.writeAndRemoveText(extractedBackgroundColor, extractedForegroundColor, innerText, escapedTextSegment, text)
 	}
 	// color the remaining part of text with background and foreground
 	r.writeColoredText(background, foreground, text)

renderer_test.go

@@ -41,6 +41,50 @@ func TestWriteColorOverride(t *testing.T) {
 	assert.NotContains(t, renderer.string(), "<#ff5733>")
 }
 
+func TestWriteColorOverrideBackground(t *testing.T) {
+	renderer := &Renderer{
+		Buffer: new(bytes.Buffer),
+	}
+	text := "This is white, <,#000000>this is black</>, white again"
+	renderer.init("pwsh")
+	renderer.write("#193549", "#ff5733", text)
+	assert.NotContains(t, renderer.string(), "000000")
+}
+
+func TestWriteColorOverrideBackground16(t *testing.T) {
+	renderer := &Renderer{
+		Buffer: new(bytes.Buffer),
+	}
+	text := "This is default <,white> this background is changed</> default again"
+	renderer.init("pwsh")
+	renderer.write("#193549", "#ff5733", text)
+	assert.NotContains(t, renderer.string(), "white")
+	assert.NotContains(t, renderer.string(), "</>")
+	assert.NotContains(t, renderer.string(), "<,")
+}
+
+func TestWriteColorOverrideBoth(t *testing.T) {
+	renderer := &Renderer{
+		Buffer: new(bytes.Buffer),
+	}
+	text := "This is white, <#000000,#ffffff>this is black</>, white again"
+	renderer.init("pwsh")
+	renderer.write("#193549", "#ff5733", text)
+	assert.NotContains(t, renderer.string(), "ffffff")
+	assert.NotContains(t, renderer.string(), "000000")
+}
+
+func TestWriteColorOverrideBoth16(t *testing.T) {
+	renderer := &Renderer{
+		Buffer: new(bytes.Buffer),
+	}
+	text := "This is white, <black,white>this is black</>, white again"
+	renderer.init("pwsh")
+	renderer.write("#193549", "#ff5733", text)
+	assert.NotContains(t, renderer.string(), "<black,white>")
+	assert.NotContains(t, renderer.string(), "</>")
+}
+
 func TestWriteColorTransparent(t *testing.T) {
 	renderer := &Renderer{
 		Buffer: new(bytes.Buffer),