Implement a big chunk of filters

filters/filter_test.go

@@ -13,12 +13,15 @@ func init() {
 	DefineStandardFilters()
 }
 
-var filterTests = []struct{ in, expected string }{
+var filterTests = []struct {
+	in       string
+	expected interface{}
+}{
 	// values
-	{`4.99 | default: 2.99`, "4.99"},
-	{`undefined | default: 2.99`, "2.99"},
-	{`false | default: 2.99`, "2.99"},
-	{`empty_list | default: 2.99`, "2.99"},
+	{`4.99 | default: 2.99`, 4.99},
+	{`undefined | default: 2.99`, 2.99},
+	{`false | default: 2.99`, 2.99},
+	{`empty_list | default: 2.99`, 2.99},
 
 	// date filters
 	{`article.published_at | date`, "Fri, Jul 17, 15"},
@@ -26,54 +29,60 @@ var filterTests = []struct{ in, expected string }{
 	{`article.published_at | date: "%Y"`, "2015"},
 	{`"2017-02-08 19:00:00 -05:00" | date`, "Wed, Feb 08, 17"},
 	{`"March 14, 2016" | date: "%b %d, %y"`, "Mar 14, 16"},
-	// {`"now" | date: "%Y-%m-%d %H:%M" }`, ""},
+	// {`"now" | date: "%Y-%m-%d %H:%M"`, "2017-06-28 13:27"},
 
 	// list filters
 	// site.pages | map: 'category' | compact | join "," %}
-	// {% assign my_array = "apples, oranges, peaches, plums" | split: ", " %}my_array.first }}
 	{`"John, Paul, George, Ringo" | split: ", " | join: " and "`, "John and Paul and George and Ringo"},
 	{`animals | sort | join: ", "`, "Sally Snake, giraffe, octopus, zebra"},
 	{`sort_prop | sort: "weight" | inspect`, `[{"weight":null},{"weight":1},{"weight":3},{"weight":5}]`},
 	{`fruits | reverse | join: ", "`, "plums, peaches, oranges, apples"},
-	// last, map, slice, sort_natural, size, uniq
+	// map, slice, sort_natural, size, uniq
 
 	// string filters
-	// "/my/fancy/url" | append: ".html"
-	// {% assign filename = "/index.html" %}"website.com" | append: filename
-
-	// "title" | capitalize
-	// "my great title" | capitalize
-
-	// "Parker Moore" | downcase
-
-	// "Have you read 'James & the Giant Peach'?" | escape
-	// "1 < 2 & 3" | escape_once
-	// "1 &lt; 2 &amp; 3" | escape_once
-
-	// lstrip, newline_to_br, prepend, remove, remove_first, replace, replace_first
-	// rstrip, split, strip, strip_html, strip_newlines, truncate, truncatewords, upcase
-	// url_decode, url_encode
+	{`"Take my protein pills and put my helmet on" | replace: "my", "your"`, "Take your protein pills and put your helmet on"},
+	{`"Take my protein pills and put my helmet on" | replace_first: "my", "your"`, "Take your protein pills and put my helmet on"},
+	{`"/my/fancy/url" | append: ".html"`, "/my/fancy/url.html"},
+	{`"website.com" | append: "/index.html"`, "website.com/index.html"},
+	{`"title" | capitalize`, "Title"},
+	{`"my great title" | capitalize`, "My great title"},
+	{`"Parker Moore" | downcase`, "parker moore"},
+	{`"Parker Moore" | upcase`, "PARKER MOORE"},
+	{`"          So much room for activities!          " | strip`, "So much room for activities!"},
+	{`"          So much room for activities!          " | lstrip`, "So much room for activities!          "},
+	{`"          So much room for activities!          " | rstrip`, "          So much room for activities!"},
+	{`"apples, oranges, and bananas" | prepend: "Some fruit: "`, "Some fruit: apples, oranges, and bananas"},
+	{`"I strained to see the train through the rain" | remove: "rain"`, "I sted to see the t through the "},
+	{`"I strained to see the train through the rain" | remove_first: "rain"`, "I sted to see the train through the rain"},
+	{`"Ground control to Major Tom." | truncate: 20`, "Ground control to..."},
+	{`"Ground control to Major Tom." | truncate: 25, ", and so on"`, "Ground control, and so on"},
+	{`"Ground control to Major Tom." | truncate: 20, ""`, "Ground control to Ma"},
+	// {`"Have you read 'James & the Giant Peach'?" | escape`, ""},
+	// {`"1 < 2 & 3" | escape_once`, ""},
+	// {`"1 &lt; 2 &amp; 3" | escape_once`, ""},
+	// newline_to_br,strip_html, strip_newlines, truncatewords, // url_decode, url_encode
 
 	// number filters
-	// -17 | abs
-	// 4 | abs
-	// "-19.86" | abs
+	{`-17 | abs`, 17},
+	{`4 | abs`, 4},
+	{`"-19.86" | abs`, 19.86},
 
-	// 1.2 | ceil
-	// 2.0 | ceil
-	// 183.357 | ceil
-	// "3.5" | ceil
+	{`1.2 | ceil`, 2},
+	{`2.0 | ceil`, 2},
+	{`183.357 | ceil`, 184},
+	{`"3.5" | ceil`, 4},
 
-	// 16 | divided_by: 4
-	// 5 | divided_by: 3
-	// 20 | divided_by: 7.0
+	// {`16 | divided_by: 4`, 4},
+	// {`5 | divided_by: 3`, 1},
+	// {`20 | divided_by: 7.0`, 123},
 
-	// 1.2 | floor
-	// 2.0 | floor
-	// 183.357 | floor
+	{`1.2 | floor`, 1},
+	{`2.0 | floor`, 2},
+	{`183.357 | floor`, 183},
 	// minus, modulo, plus, round,times
 
-	// Jekyll extensions
+	// Jekyll extensions; added here for convenient testing
+	// TODO add this just to the test environment
 	{`obj | inspect`, `{"a":1}`},
 }
 
@@ -122,11 +131,12 @@ func TestFilters(t *testing.T) {
 		t.Run(fmt.Sprintf("%02d", i), func(t *testing.T) {
 			value, err := expressions.EvaluateExpr(test.in, filterTestContext)
 			require.NoErrorf(t, err, test.in)
-			actual := fmt.Sprintf("%v", value)
-			if value == nil {
-				actual = ""
+			expected := test.expected
+			switch ex := expected.(type) {
+			case int:
+				expected = float64(ex)
 			}
-			require.Equalf(t, test.expected, actual, test.in)
+			require.Equalf(t, expected, value, test.in)
 		})
 	}
 }

filters/filters.go

@@ -4,8 +4,10 @@ package filters
 import (
 	"encoding/json"
 	"fmt"
+	"math"
 	"strings"
 	"time"
+	"unicode"
 
 	"github.com/leekchan/timeutil"
 	"github.com/osteele/liquid/expressions"
@@ -36,8 +38,65 @@ func DefineStandardFilters() {
 	expressions.DefineFilter("reverse", reverseFilter)
 	expressions.DefineFilter("sort", sortFilter)
 
+	// numbers
+	expressions.DefineFilter("abs", math.Abs)
+	expressions.DefineFilter("ceil", math.Ceil)
+	expressions.DefineFilter("floor", math.Floor)
+
 	// strings
+	expressions.DefineFilter("append", func(s, suffix string) string {
+		return s + suffix
+	})
+	expressions.DefineFilter("capitalize", func(s, suffix string) string {
+		if len(s) < 1 {
+			return s
+		}
+		return strings.ToUpper(s[:1]) + s[1:]
+	})
+	expressions.DefineFilter("downcase", func(s, suffix string) string {
+		return strings.ToLower(s)
+	})
+	// expressions.DefineFilter("escape", func(s, suffix string) string {
+	// 	buf := new(bytes.Buffer)
+	// 	template.HTMLEscape(buf, []byte(s))
+	// 	return buf.String()
+	// })
+	expressions.DefineFilter("prepend", func(s, prefix string) string {
+		return prefix + s
+	})
+	expressions.DefineFilter("remove", func(s, old string) string {
+		return strings.Replace(s, old, "", -1)
+	})
+	expressions.DefineFilter("remove_first", func(s, old string) string {
+		return strings.Replace(s, old, "", 1)
+	})
+	expressions.DefineFilter("replace", func(s, old, new string) string {
+		return strings.Replace(s, old, new, -1)
+	})
+	expressions.DefineFilter("replace_first", func(s, old, new string) string {
+		return strings.Replace(s, old, new, 1)
+	})
 	expressions.DefineFilter("split", splitFilter)
+	expressions.DefineFilter("strip", strings.TrimSpace)
+	expressions.DefineFilter("lstrip", func(s string) string {
+		return strings.TrimLeftFunc(s, unicode.IsSpace)
+	})
+	expressions.DefineFilter("rstrip", func(s string) string {
+		return strings.TrimRightFunc(s, unicode.IsSpace)
+	})
+	expressions.DefineFilter("truncate", func(s string, n int, ellipsis interface{}) string {
+		el, ok := ellipsis.(string)
+		if !ok {
+			el = "..."
+		}
+		if len(s) > n {
+			s = s[:n-len(el)] + el
+		}
+		return s
+	})
+	expressions.DefineFilter("upcase", func(s, suffix string) string {
+		return strings.ToUpper(s)
+	})
 
 	// Jekyll
 	expressions.DefineFilter("inspect", json.Marshal)

generics/convert.go

@@ -2,6 +2,7 @@ package generics
 
 import (
 	"reflect"
+	"strconv"
 	"time"
 )
 
@@ -10,6 +11,8 @@ var timeType = reflect.TypeOf(time.Now())
 // Convert value to the type. This is a more aggressive conversion, that will
 // recursively create new map and slice values as necessary. It doesn't
 // handle circular references.
+//
+// TODO It's weird that this takes an interface{} but returns a Value
 func Convert(value interface{}, t reflect.Type) reflect.Value {
 	r := reflect.ValueOf(value)
 	if r.Type().ConvertibleTo(t) {
@@ -26,6 +29,18 @@ func Convert(value interface{}, t reflect.Type) reflect.Value {
 		return reflect.ValueOf(v)
 	}
 	switch t.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		n, err := strconv.Atoi(value.(string))
+		if err != nil {
+			panic(err)
+		}
+		return reflect.ValueOf(n)
+	case reflect.Float32, reflect.Float64:
+		n, err := strconv.ParseFloat(value.(string), 64)
+		if err != nil {
+			panic(err)
+		}
+		return reflect.ValueOf(n)
 	case reflect.Slice:
 		if r.Kind() != reflect.Array && r.Kind() != reflect.Slice {
 			break

generics/generics_test.go

@@ -2,11 +2,20 @@ package generics
 
 import (
 	"fmt"
+	"reflect"
 	"testing"
 
 	"github.com/stretchr/testify/require"
 )
 
+var convertTests = []struct {
+	value, proto, expected interface{}
+}{
+	{1, 1.0, float64(1)},
+	{"2", 1, int(2)},
+	{"1.2", 1.0, float64(1.2)},
+}
+
 var eqTests = []struct {
 	a, b     interface{}
 	expected bool
@@ -52,6 +61,16 @@ var lessTests = []struct {
 	{[]string{"a"}, []string{"a"}, false},
 }
 
+func TestConvert(t *testing.T) {
+	for i, test := range convertTests {
+		t.Run(fmt.Sprintf("%02d", i+1), func(t *testing.T) {
+			typ := reflect.TypeOf(test.proto)
+			value := Convert(test.value, typ).Interface()
+			require.Equalf(t, test.expected, value, "Convert %#v -> %#v", test.value, test, typ)
+		})
+	}
+}
+
 func TestEqual(t *testing.T) {
 	for i, test := range eqTests {
 		t.Run(fmt.Sprintf("%02d", i+1), func(t *testing.T) {