Support field index expressions in preview and execute action

Also close #679. The placeholder for the current query is {q}.

src/terminal_test.go

@@ -0,0 +1,73 @@
+package fzf
+
+import (
+	"regexp"
+	"testing"
+
+	"github.com/junegunn/fzf/src/util"
+)
+
+func newItem(str string) *Item {
+	bytes := []byte(str)
+	trimmed, _, _ := extractColor(str, nil, nil)
+	return &Item{origText: &bytes, text: util.RunesToChars([]rune(trimmed))}
+}
+
+func TestReplacePlaceholder(t *testing.T) {
+	items1 := []*Item{newItem("  foo'bar \x1b[31mbaz\x1b[m")}
+	items2 := []*Item{
+		newItem("foo'bar \x1b[31mbaz\x1b[m"),
+		newItem("FOO'BAR \x1b[31mBAZ\x1b[m")}
+
+	var result string
+	check := func(expected string) {
+		if result != expected {
+			t.Errorf("expected: %s, actual: %s", expected, result)
+		}
+	}
+
+	// {}, preserve ansi
+	result = replacePlaceholder("echo {}", false, Delimiter{}, "query", items1)
+	check("echo '  foo'\\''bar \x1b[31mbaz\x1b[m'")
+
+	// {}, strip ansi
+	result = replacePlaceholder("echo {}", true, Delimiter{}, "query", items1)
+	check("echo '  foo'\\''bar baz'")
+
+	// {}, with multiple items
+	result = replacePlaceholder("echo {}", true, Delimiter{}, "query", items2)
+	check("echo 'foo'\\''bar baz' 'FOO'\\''BAR BAZ'")
+
+	// {..}, strip leading whitespaces, preserve ansi
+	result = replacePlaceholder("echo {..}", false, Delimiter{}, "query", items1)
+	check("echo 'foo'\\''bar \x1b[31mbaz\x1b[m'")
+
+	// {..}, strip leading whitespaces, strip ansi
+	result = replacePlaceholder("echo {..}", true, Delimiter{}, "query", items1)
+	check("echo 'foo'\\''bar baz'")
+
+	// {q}
+	result = replacePlaceholder("echo {} {q}", true, Delimiter{}, "query", items1)
+	check("echo '  foo'\\''bar baz' 'query'")
+
+	// {q}, multiple items
+	result = replacePlaceholder("echo {}{q}{}", true, Delimiter{}, "query 'string'", items2)
+	check("echo 'foo'\\''bar baz' 'FOO'\\''BAR BAZ''query '\\''string'\\''''foo'\\''bar baz' 'FOO'\\''BAR BAZ'")
+
+	result = replacePlaceholder("echo {1}/{2}/{2,1}/{-1}/{-2}/{}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, "query", items1)
+	check("echo 'foo'\\''bar'/'baz'/'bazfoo'\\''bar'/'baz'/'foo'\\''bar'/'  foo'\\''bar baz'/'foo'\\''bar baz'/{n.t}/{}/{1}/{q}/''")
+
+	result = replacePlaceholder("echo {1}/{2}/{-1}/{-2}/{..}/{n.t}/\\{}/\\{1}/\\{q}/{3}", true, Delimiter{}, "query", items2)
+	check("echo 'foo'\\''bar' 'FOO'\\''BAR'/'baz' 'BAZ'/'baz' 'BAZ'/'foo'\\''bar' 'FOO'\\''BAR'/'foo'\\''bar baz' 'FOO'\\''BAR BAZ'/{n.t}/{}/{1}/{q}/'' ''")
+
+	// String delimiter
+	delim := "'"
+	result = replacePlaceholder("echo {}/{1}/{2}", true, Delimiter{str: &delim}, "query", items1)
+	check("echo '  foo'\\''bar baz'/'foo'/'bar baz'")
+
+	// Regex delimiter
+	regex := regexp.MustCompile("[oa]+")
+	// foo'bar baz
+	result = replacePlaceholder("echo {}/{1}/{3}/{2..3}", true, Delimiter{regex: regex}, "query", items1)
+	check("echo '  foo'\\''bar baz'/'f'/'r b'/''\\''bar b'")
+}