From ea5b4fdefe4a16f4eecf98e6fbe59ad2446bb37a Mon Sep 17 00:00:00 2001
From: Johan Walles <johan.walles@gmail.com>
Date: Sat, 6 Jul 2019 13:51:48 +0200
Subject: [PATCH] Extract search string compilation into its own testable
 function

---
 m/pager.go      | 33 +++++++++++++++++++++------------
 m/pager_test.go |  4 ++++
 2 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/m/pager.go b/m/pager.go
index 15279b6..808ecf0 100644
--- a/m/pager.go
+++ b/m/pager.go
@@ -260,28 +260,37 @@ func (p *_Pager) _ScrollToPreviousSearchHit() {
 }
 
 func (p *_Pager) _UpdateSearchPattern() {
-	if len(p.searchString) == 0 {
-		p.searchPattern = nil
-		return
+	p.searchPattern = ToPattern(p.searchString)
+
+	p._ScrollToSearchHits()
+
+	// FIXME: If the user is typing, indicate to user if we didn't find anything
+}
+
+// ToPattern compiles a search string into a pattern.
+//
+// If the string contains only lower-case letter the pattern will be case insensitive.
+//
+// If the string is empty the pattern will be nil.
+//
+// If the string does not compile into a regexp the pattern will match the string verbatim
+func ToPattern(compileMe string) *regexp.Regexp {
+	if len(compileMe) == 0 {
+		return nil
 	}
 
-	defer p._ScrollToSearchHits()
-	// FIXME: Indicate to user if we didn't find anything
-
-	pattern, err := regexp.Compile(p.searchString)
+	pattern, err := regexp.Compile(compileMe)
 	if err == nil {
 		// Search string is a regexp
 		// FIXME: Make this case insensitive if input is all-lowercase
-		p.searchPattern = pattern
-		return
+		return pattern
 	}
 
-	pattern, err = regexp.Compile(regexp.QuoteMeta(p.searchString))
+	pattern, err = regexp.Compile(regexp.QuoteMeta(compileMe))
 	if err == nil {
 		// Pattern matching the string exactly
 		// FIXME: Make this case insensitive if input is all-lowercase
-		p.searchPattern = pattern
-		return
+		return pattern
 	}
 
 	// Unable to create a match-string-verbatim pattern
diff --git a/m/pager_test.go b/m/pager_test.go
index f0a8739..ea1fef5 100644
--- a/m/pager_test.go
+++ b/m/pager_test.go
@@ -215,3 +215,7 @@ func TestManPageFormatting(t *testing.T) {
 
 	// FIXME: Test backspace between two uncombinable characters
 }
+
+func TestToPattern(t *testing.T) {
+	assert.Assert(t, ToPattern("") == nil)
+}