Add {fzf:prompt} placeholder expression

Close #3354

4 files changed, 100 insertions, 58 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f46d0f08..baee4046 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,8 +17,9 @@ CHANGELOG
         --bind 'focus:transform:[[ -n {} ]] && exit; [[ {fzf:action} =~ up$ ]] && echo up || echo down'
   ```
 - Added placeholder expressions
-    - `{fzf:action}` - the name of the last action performed
-    - `{fzf:query}` - synonym for `{q}`
+    - `{fzf:action}` - The name of the last action performed
+    - `{fzf:prompt}` - Prompt string (including ANSI color codes)
+    - `{fzf:query}` - Synonym for `{q}`
 - Added support for negative height
   ```sh
   # Terminal height minus 1, so you can still see the command line
diff --git a/man/man1/fzf.1 b/man/man1/fzf.1
index fd68a874..9b5e1e3a 100644
--- a/man/man1/fzf.1
+++ b/man/man1/fzf.1
@@ -593,6 +593,7 @@ Also,
   Use \fB{+n}\fR if you want all index numbers when multiple lines are selected.
 .br
 * \fB{fzf:action}\fR is replaced to to the name of the last action performed
+* \fB{fzf:prompt}\fR is replaced to to the prompt string
 
 Note that you can escape a placeholder pattern by prepending a backslash.
 
diff --git a/src/terminal.go b/src/terminal.go
index ad860441..13855925 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -57,7 +57,7 @@ var actionTypeRegex *regexp.Regexp
 const clearCode string = "\x1b[2J"
 
 func init() {
-	placeholder = regexp.MustCompile(`\\?(?:{[+sf]*[0-9,-.]*}|{q}|{fzf:(?:query|action)}|{\+?f?nf?})`)
+	placeholder = regexp.MustCompile(`\\?(?:{[+sf]*[0-9,-.]*}|{q}|{fzf:(?:query|action|prompt)}|{\+?f?nf?})`)
 	whiteSuffix = regexp.MustCompile(`\s*$`)
 	offsetComponentRegex = regexp.MustCompile(`([+-][0-9]+)|(-?/[1-9][0-9]*)`)
 	offsetTrimCharsRegex = regexp.MustCompile(`[^0-9/+-]`)
@@ -183,6 +183,7 @@ type Terminal struct {
 	separator          labelPrinter
 	separatorLen       int
 	spinner            []string
+	promptString       string
 	prompt             func()
 	promptLen          int
 	borderLabel        labelPrinter
@@ -670,6 +671,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		infoSep:            opts.InfoSep,
 		separator:          nil,
 		spinner:            makeSpinner(opts.Unicode),
+		promptString:       opts.Prompt,
 		queryLen:           [2]int{0, 0},
 		layout:             opts.Layout,
 		fullscreen:         fullscreen,
@@ -2354,7 +2356,7 @@ func parsePlaceholder(match string) (bool, string, placeholderFlags) {
 	}
 
 	if strings.HasPrefix(match, "{fzf:") {
-		// Both {fzf:query} and {fzf:action} are not determined by the current item
+		// {fzf:*} are not determined by the current item
 		flags.forceUpdate = true
 		return false, match, flags
 	}
@@ -2421,9 +2423,30 @@ func cleanTemporaryFiles() {
 	activeTempFiles = []string{}
 }
 
+type replacePlaceholderParams struct {
+	template   string
+	stripAnsi  bool
+	delimiter  Delimiter
+	printsep   string
+	forcePlus  bool
+	query      string
+	allItems   []*Item
+	lastAction actionType
+	prompt     string
+}
+
 func (t *Terminal) replacePlaceholder(template string, forcePlus bool, input string, list []*Item) string {
-	return replacePlaceholder(
-		template, t.ansi, t.delimiter, t.printsep, forcePlus, input, list, t.lastAction)
+	return replacePlaceholder(replacePlaceholderParams{
+		template:   template,
+		stripAnsi:  t.ansi,
+		delimiter:  t.delimiter,
+		printsep:   t.printsep,
+		forcePlus:  forcePlus,
+		query:      input,
+		allItems:   list,
+		lastAction: t.lastAction,
+		prompt:     t.promptString,
+	})
 }
 
 func (t *Terminal) evaluateScrollOffset() int {
@@ -2461,9 +2484,9 @@ func (t *Terminal) evaluateScrollOffset() int {
 	return util.Max(0, base)
 }
 
-func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, printsep string, forcePlus bool, query string, allItems []*Item, lastAction actionType) string {
-	current := allItems[:1]
-	selected := allItems[1:]
+func replacePlaceholder(params replacePlaceholderParams) string {
+	current := params.allItems[:1]
+	selected := params.allItems[1:]
 	if current[0] == nil {
 		current = []*Item{}
 	}
@@ -2472,7 +2495,7 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 	}
 
 	// replace placeholders one by one
-	return placeholder.ReplaceAllStringFunc(template, func(match string) string {
+	return placeholder.ReplaceAllStringFunc(params.template, func(match string) string {
 		escaped, match, flags := parsePlaceholder(match)
 
 		// this function implements the effects a placeholder has on items
@@ -2482,17 +2505,8 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 		switch {
 		case escaped:
 			return match
-		case match == "{fzf:action}":
-			name := ""
-			for i, r := range lastAction.String()[3:] {
-				if i > 0 && r >= 'A' && r <= 'Z' {
-					name += "-"
-				}
-				name += string(r)
-			}
-			return strings.ToLower(name)
 		case match == "{q}" || match == "{fzf:query}":
-			return quoteEntry(query)
+			return quoteEntry(params.query)
 		case match == "{}":
 			replace = func(item *Item) string {
 				switch {
@@ -2503,11 +2517,22 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 					}
 					return strconv.Itoa(n)
 				case flags.file:
-					return item.AsString(stripAnsi)
+					return item.AsString(params.stripAnsi)
 				default:
-					return quoteEntry(item.AsString(stripAnsi))
+					return quoteEntry(item.AsString(params.stripAnsi))
 				}
 			}
+		case match == "{fzf:action}":
+			name := ""
+			for i, r := range params.lastAction.String()[3:] {
+				if i > 0 && r >= 'A' && r <= 'Z' {
+					name += "-"
+				}
+				name += string(r)
+			}
+			return strings.ToLower(name)
+		case match == "{fzf:prompt}":
+			return quoteEntry(params.prompt)
 		default:
 			// token type and also failover (below)
 			rangeExpressions := strings.Split(match[1:len(match)-1], ",")
@@ -2522,15 +2547,15 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 			}
 
 			replace = func(item *Item) string {
-				tokens := Tokenize(item.AsString(stripAnsi), delimiter)
+				tokens := Tokenize(item.AsString(params.stripAnsi), params.delimiter)
 				trans := Transform(tokens, ranges)
 				str := joinTokens(trans)
 
 				// trim the last delimiter
-				if delimiter.str != nil {
-					str = strings.TrimSuffix(str, *delimiter.str)
-				} else if delimiter.regex != nil {
-					delims := delimiter.regex.FindAllStringIndex(str, -1)
+				if params.delimiter.str != nil {
+					str = strings.TrimSuffix(str, *params.delimiter.str)
+				} else if params.delimiter.regex != nil {
+					delims := params.delimiter.regex.FindAllStringIndex(str, -1)
 					// make sure the delimiter is at the very end of the string
 					if len(delims) > 0 && delims[len(delims)-1][1] == len(str) {
 						str = str[:delims[len(delims)-1][0]]
@@ -2550,7 +2575,7 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 		// apply 'replace' function over proper set of items and return result
 
 		items := current
-		if flags.plus || forcePlus {
+		if flags.plus || params.forcePlus {
 			items = selected
 		}
 		replacements := make([]string, len(items))
@@ -2560,7 +2585,7 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 		}
 
 		if flags.file {
-			return writeTemporaryFile(replacements, printsep)
+			return writeTemporaryFile(replacements, params.printsep)
 		}
 		return strings.Join(replacements, " ")
 	})
@@ -3302,6 +3327,7 @@ func (t *Terminal) Loop() {
 				}
 			case actTransformPrompt:
 				prompt := t.executeCommand(a.a, false, true, true, true)
+				t.promptString = prompt
 				t.prompt, t.promptLen = t.parsePrompt(prompt)
 				req(reqPrompt)
 			case actTransformQuery:
@@ -3395,6 +3421,7 @@ func (t *Terminal) Loop() {
 					req(reqRedrawPreviewLabel)
 				}
 			case actChangePrompt:
+				t.promptString = a.a
 				t.prompt, t.promptLen = t.parsePrompt(a.a)
 				req(reqPrompt)
 			case actPreview:
diff --git a/src/terminal_test.go b/src/terminal_test.go
index 791bebf4..e7d3e751 100644
--- a/src/terminal_test.go
+++ b/src/terminal_test.go
@@ -12,6 +12,20 @@ import (
 	"github.com/junegunn/fzf/src/util"
 )
 
+func replacePlaceholderTest(template string, stripAnsi bool, delimiter Delimiter, printsep string, forcePlus bool, query string, allItems []*Item) string {
+	return replacePlaceholder(replacePlaceholderParams{
+		template:   template,
+		stripAnsi:  stripAnsi,
+		delimiter:  delimiter,
+		printsep:   printsep,
+		forcePlus:  forcePlus,
+		query:      query,
+		allItems:   allItems,
+		lastAction: actBackwardDeleteCharEof,
+		prompt:     "prompt",
+	})
+}
+
 func TestReplacePlaceholder(t *testing.T) {
 	item1 := newItem("  foo'bar \x1b[31mbaz\x1b[m")
 	items1 := []*Item{item1, item1}
@@ -52,90 +66,90 @@ func TestReplacePlaceholder(t *testing.T) {
 	*/
 
 	// {}, preserve ansi
-	result = replacePlaceholder("echo {}", false, Delimiter{}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {}", false, Delimiter{}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  foo{{.I}}bar \x1b[31mbaz\x1b[m{{.O}}")
 
 	// {}, strip ansi
-	result = replacePlaceholder("echo {}", true, Delimiter{}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {}", true, Delimiter{}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  foo{{.I}}bar baz{{.O}}")
 
 	// {}, with multiple items
-	result = replacePlaceholder("echo {}", true, Delimiter{}, printsep, false, "query", items2, actIgnore)
+	result = replacePlaceholderTest("echo {}", true, Delimiter{}, printsep, false, "query", items2)
 	checkFormat("echo {{.O}}foo{{.I}}bar baz{{.O}}")
 
 	// {..}, strip leading whitespaces, preserve ansi
-	result = replacePlaceholder("echo {..}", false, Delimiter{}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {..}", false, Delimiter{}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}foo{{.I}}bar \x1b[31mbaz\x1b[m{{.O}}")
 
 	// {..}, strip leading whitespaces, strip ansi
-	result = replacePlaceholder("echo {..}", true, Delimiter{}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {..}", true, Delimiter{}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}foo{{.I}}bar baz{{.O}}")
 
 	// {q}
-	result = replacePlaceholder("echo {} {q}", true, Delimiter{}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {} {q}", true, Delimiter{}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  foo{{.I}}bar baz{{.O}} {{.O}}query{{.O}}")
 
 	// {q}, multiple items
-	result = replacePlaceholder("echo {+}{q}{+}", true, Delimiter{}, printsep, false, "query 'string'", items2, actIgnore)
+	result = replacePlaceholderTest("echo {+}{q}{+}", true, Delimiter{}, printsep, false, "query 'string'", items2)
 	checkFormat("echo {{.O}}foo{{.I}}bar baz{{.O}} {{.O}}FOO{{.I}}BAR BAZ{{.O}}{{.O}}query {{.I}}string{{.I}}{{.O}}{{.O}}foo{{.I}}bar baz{{.O}} {{.O}}FOO{{.I}}BAR BAZ{{.O}}")
 
-	result = replacePlaceholder("echo {}{q}{}", true, Delimiter{}, printsep, false, "query 'string'", items2, actIgnore)
+	result = replacePlaceholderTest("echo {}{q}{}", true, Delimiter{}, printsep, false, "query 'string'", items2)
 	checkFormat("echo {{.O}}foo{{.I}}bar baz{{.O}}{{.O}}query {{.I}}string{{.I}}{{.O}}{{.O}}foo{{.I}}bar baz{{.O}}")
 
-	result = replacePlaceholder("echo {1}/{2}/{2,1}/{-1}/{-2}/{}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {1}/{2}/{2,1}/{-1}/{-2}/{}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}foo{{.I}}bar{{.O}}/{{.O}}baz{{.O}}/{{.O}}bazfoo{{.I}}bar{{.O}}/{{.O}}baz{{.O}}/{{.O}}foo{{.I}}bar{{.O}}/{{.O}}  foo{{.I}}bar baz{{.O}}/{{.O}}foo{{.I}}bar baz{{.O}}/{n.t}/{}/{1}/{q}/{{.O}}{{.O}}")
 
-	result = replacePlaceholder("echo {1}/{2}/{-1}/{-2}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, printsep, false, "query", items2, actIgnore)
+	result = replacePlaceholderTest("echo {1}/{2}/{-1}/{-2}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, printsep, false, "query", items2)
 	checkFormat("echo {{.O}}foo{{.I}}bar{{.O}}/{{.O}}baz{{.O}}/{{.O}}baz{{.O}}/{{.O}}foo{{.I}}bar{{.O}}/{{.O}}foo{{.I}}bar baz{{.O}}/{n.t}/{}/{1}/{q}/{{.O}}{{.O}}")
 
-	result = replacePlaceholder("echo {+1}/{+2}/{+-1}/{+-2}/{+..}/{n.t}/\\{}/\\{1}/\\{q}/{+3}", true, Delimiter{}, printsep, false, "query", items2, actIgnore)
+	result = replacePlaceholderTest("echo {+1}/{+2}/{+-1}/{+-2}/{+..}/{n.t}/\\{}/\\{1}/\\{q}/{+3}", true, Delimiter{}, printsep, false, "query", items2)
 	checkFormat("echo {{.O}}foo{{.I}}bar{{.O}} {{.O}}FOO{{.I}}BAR{{.O}}/{{.O}}baz{{.O}} {{.O}}BAZ{{.O}}/{{.O}}baz{{.O}} {{.O}}BAZ{{.O}}/{{.O}}foo{{.I}}bar{{.O}} {{.O}}FOO{{.I}}BAR{{.O}}/{{.O}}foo{{.I}}bar baz{{.O}} {{.O}}FOO{{.I}}BAR BAZ{{.O}}/{n.t}/{}/{1}/{q}/{{.O}}{{.O}} {{.O}}{{.O}}")
 
 	// forcePlus
-	result = replacePlaceholder("echo {1}/{2}/{-1}/{-2}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, printsep, true, "query", items2, actIgnore)
+	result = replacePlaceholderTest("echo {1}/{2}/{-1}/{-2}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, printsep, true, "query", items2)
 	checkFormat("echo {{.O}}foo{{.I}}bar{{.O}} {{.O}}FOO{{.I}}BAR{{.O}}/{{.O}}baz{{.O}} {{.O}}BAZ{{.O}}/{{.O}}baz{{.O}} {{.O}}BAZ{{.O}}/{{.O}}foo{{.I}}bar{{.O}} {{.O}}FOO{{.I}}BAR{{.O}}/{{.O}}foo{{.I}}bar baz{{.O}} {{.O}}FOO{{.I}}BAR BAZ{{.O}}/{n.t}/{}/{1}/{q}/{{.O}}{{.O}} {{.O}}{{.O}}")
 
 	// Whitespace preserving flag with "'" delimiter
-	result = replacePlaceholder("echo {s1}", true, Delimiter{str: &delim}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {s1}", true, Delimiter{str: &delim}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  foo{{.O}}")
 
-	result = replacePlaceholder("echo {s2}", true, Delimiter{str: &delim}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {s2}", true, Delimiter{str: &delim}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}bar baz{{.O}}")
 
-	result = replacePlaceholder("echo {s}", true, Delimiter{str: &delim}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {s}", true, Delimiter{str: &delim}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  foo{{.I}}bar baz{{.O}}")
 
-	result = replacePlaceholder("echo {s..}", true, Delimiter{str: &delim}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {s..}", true, Delimiter{str: &delim}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  foo{{.I}}bar baz{{.O}}")
 
 	// Whitespace preserving flag with regex delimiter
 	regex = regexp.MustCompile(`\w+`)
 
-	result = replacePlaceholder("echo {s1}", true, Delimiter{regex: regex}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {s1}", true, Delimiter{regex: regex}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  {{.O}}")
 
-	result = replacePlaceholder("echo {s2}", true, Delimiter{regex: regex}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {s2}", true, Delimiter{regex: regex}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}{{.I}}{{.O}}")
 
-	result = replacePlaceholder("echo {s3}", true, Delimiter{regex: regex}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {s3}", true, Delimiter{regex: regex}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}} {{.O}}")
 
 	// No match
-	result = replacePlaceholder("echo {}/{+}", true, Delimiter{}, printsep, false, "query", []*Item{nil, nil}, actIgnore)
+	result = replacePlaceholderTest("echo {}/{+}", true, Delimiter{}, printsep, false, "query", []*Item{nil, nil})
 	check("echo /")
 
 	// No match, but with selections
-	result = replacePlaceholder("echo {}/{+}", true, Delimiter{}, printsep, false, "query", []*Item{nil, item1}, actIgnore)
+	result = replacePlaceholderTest("echo {}/{+}", true, Delimiter{}, printsep, false, "query", []*Item{nil, item1})
 	checkFormat("echo /{{.O}}  foo{{.I}}bar baz{{.O}}")
 
 	// String delimiter
-	result = replacePlaceholder("echo {}/{1}/{2}", true, Delimiter{str: &delim}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {}/{1}/{2}", true, Delimiter{str: &delim}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  foo{{.I}}bar baz{{.O}}/{{.O}}foo{{.O}}/{{.O}}bar baz{{.O}}")
 
 	// Regex delimiter
 	regex = regexp.MustCompile("[oa]+")
 	// foo'bar baz
-	result = replacePlaceholder("echo {}/{1}/{3}/{2..3}", true, Delimiter{regex: regex}, printsep, false, "query", items1, actIgnore)
+	result = replacePlaceholderTest("echo {}/{1}/{3}/{2..3}", true, Delimiter{regex: regex}, printsep, false, "query", items1)
 	checkFormat("echo {{.O}}  foo{{.I}}bar baz{{.O}}/{{.O}}f{{.O}}/{{.O}}r b{{.O}}/{{.O}}{{.I}}bar b{{.O}}")
 
 	/*
@@ -155,7 +169,6 @@ func TestReplacePlaceholder(t *testing.T) {
 		newItem("7a 7b 7c 7d 7e 7f"),
 	}
 	stripAnsi := false
-	printsep = "\n"
 	forcePlus := false
 	query := "sample query"
 
@@ -199,7 +212,7 @@ func TestReplacePlaceholder(t *testing.T) {
 	// while the double q is invalid, it is useful here for testing purposes
 	templateToOutput[`{q}`] = "{{.O}}" + query + "{{.O}}"
 	templateToOutput[`{fzf:query}`] = "{{.O}}" + query + "{{.O}}"
-	templateToOutput[`{fzf:action}`] = "backward-delete-char-eof"
+	templateToOutput[`{fzf:action} {fzf:prompt}`] = "backward-delete-char-eof 'prompt'"
 
 	// IV. escaping placeholder
 	templateToOutput[`\{}`] = `{}`
@@ -210,11 +223,11 @@ func TestReplacePlaceholder(t *testing.T) {
 	templateToOutput[`{++}`] = templateToOutput[`{+}`]
 
 	for giveTemplate, wantOutput := range templateToOutput {
-		result = replacePlaceholder(giveTemplate, stripAnsi, Delimiter{}, printsep, forcePlus, query, items3, actBackwardDeleteCharEof)
+		result = replacePlaceholderTest(giveTemplate, stripAnsi, Delimiter{}, printsep, forcePlus, query, items3)
 		checkFormat(wantOutput)
 	}
 	for giveTemplate, wantOutput := range templateToFile {
-		path := replacePlaceholder(giveTemplate, stripAnsi, Delimiter{}, printsep, forcePlus, query, items3, actIgnore)
+		path := replacePlaceholderTest(giveTemplate, stripAnsi, Delimiter{}, printsep, forcePlus, query, items3)
 
 		data, err := readFile(path)
 		if err != nil {
@@ -568,10 +581,10 @@ func testCommands(t *testing.T, tests []testCase) {
 
 	// evaluate the test cases
 	for idx, test := range tests {
-		gotOutput := replacePlaceholder(
+		gotOutput := replacePlaceholderTest(
 			test.give.template, stripAnsi, delimiter, printsep, forcePlus,
 			test.give.query,
-			test.give.allItems, actIgnore)
+			test.give.allItems)
 		switch {
 		case test.want.output != "":
 			if gotOutput != test.want.output {