Add StrBefore, StrAfter and StrBetween methods

strafter.go

@@ -0,0 +1,24 @@
+package strutil
+
+import "strings"
+
+func StrAfter(str string, search string) string {
+	pos := strings.Index(str, search)
+	return StrAfterIndex(str, search, pos)
+}
+
+func StrAfterLast(str string, search string) string {
+	pos := strings.LastIndex(str, search)
+	return StrAfterIndex(str, search, pos)
+}
+
+func StrAfterIndex(str string, search string, pos int) string {
+	if pos == -1 {
+		return ""
+	}
+	adjustedPos := pos + len(search)
+	if adjustedPos >= len(str) {
+		return ""
+	}
+	return strings.Trim(str[adjustedPos:len(str)], " ")
+}

strafter_test.go

@@ -0,0 +1,34 @@
+package strutil
+
+import "testing"
+
+func TestStrAfter(t *testing.T) {
+	tests := []struct {
+		input    string
+		search   string
+		expected string
+	}{
+		{"Return every word after this word", "word", "after this word"},
+		{"it's not contained", "nothing", ""},
+	}
+
+	for i, test := range tests {
+		output := StrAfter(test.input, test.search)
+		Assert(t, test.expected, output, "Test case %d is not successful\n", i)
+	}
+}
+
+func TestStrAfterLast(t *testing.T) {
+	tests := []struct {
+		input    string
+		search   string
+		expected string
+	}{
+		{"Return every word after the word last occurance", "word", "last occurance"},
+	}
+
+	for i, test := range tests {
+		output := StrAfterLast(test.input, test.search)
+		Assert(t, test.expected, output, "Test case %d is not successful\n", i)
+	}
+}

strbefore.go

@@ -0,0 +1,19 @@
+package strutil
+
+import "strings"
+
+func StrBefore(str string, search string) string {
+	pos := strings.Index(str, search)
+	if pos == -1 {
+		return ""
+	}
+	return strings.Trim(str[0:pos], " ")
+}
+
+func StrBeforeLast(str string, search string) string {
+	pos := strings.LastIndex(str, search)
+	if pos == -1 {
+		return ""
+	}
+	return strings.Trim(str[0:pos], " ")
+}

strbefore_test.go

@@ -0,0 +1,33 @@
+package strutil
+
+import "testing"
+
+func TestStrBefore(t *testing.T) {
+	tests := []struct {
+		input    string
+		search   string
+		expected string
+	}{
+		{"before this", "this", "before"},
+	}
+
+	for i, test := range tests {
+		output := StrBefore(test.input, test.search)
+		Assert(t, test.expected, output, "Test case %d is not successful\n", i)
+	}
+}
+
+func TestStrBeforeLast(t *testing.T) {
+	tests := []struct {
+		input    string
+		search   string
+		expected string
+	}{
+		{"before this is this", "this", "before this is"},
+	}
+
+	for i, test := range tests {
+		output := StrBeforeLast(test.input, test.search)
+		Assert(t, test.expected, output, "Test case %d is not successful\n", i)
+	}
+}

strbetween.go

@@ -0,0 +1,19 @@
+package strutil
+
+import "strings"
+
+func StrBetween(str string, a string, b string) string {
+	posFirst := strings.Index(str, a)
+	if posFirst == -1 {
+		return ""
+	}
+	posLast := strings.Index(str, b)
+	if posLast == -1 {
+		return ""
+	}
+	posFirstAdjusted := posFirst + len(a)
+	if posFirstAdjusted >= posLast {
+		return ""
+	}
+	return strings.Trim(str[posFirstAdjusted:posLast], " ")
+}

strbetween_test.go

@@ -0,0 +1,19 @@
+package strutil
+
+import "testing"
+
+func TestStrBetween(t *testing.T) {
+	tests := []struct {
+		input    string
+		a        string
+		b        string
+		expected string
+	}{
+		{"between this and that", "this", "that", "and"},
+	}
+
+	for i, test := range tests {
+		output := StrBetween(test.input, test.a, test.b)
+		Assert(t, test.expected, output, "Test case %d is not successful\n", i)
+	}
+}