Add URL parser

app_test.go

@@ -9,7 +9,7 @@ import (
 func TestChooseTemplate(t *testing.T) {
 	tmpl, err := template.ParseGlob("templates/*")
 	if err != nil {
-		t.Errorf("Unable to load templates: %v", err)
+		t.Errorf("unable to load templates: %v", err)
 	}
 	app := &Datetime{tmpl: tmpl}
 

go.mod

@@ -3,6 +3,7 @@ module github.com/serverwentdown/datetime.link
 go 1.14
 
 require (
+	github.com/google/go-cmp v0.5.2
 	github.com/hbollon/go-edlib v1.3.1
 	go.uber.org/zap v1.16.0
 )

go.sum

@@ -1,6 +1,8 @@
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/go-cmp v0.5.2 h1:X2ev0eStA3AbceY54o37/0PQ/UWqKEiiO2dKL5OPaFM=
+github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/hbollon/go-edlib v1.3.1 h1:3x2Faq1xbShKhel5wEYyCNZFguh+s8GH75jdp8w6phU=
 github.com/hbollon/go-edlib v1.3.1/go.mod h1:wnt6o6EIVEzUfgbUZY7BerzQ2uvzp354qmS2xaLkrhM=
@@ -37,6 +39,7 @@ golang.org/x/tools v0.0.0-20190621195816-6e04913cbbac/go.mod h1:/rFqwRUd4F7ZHNgw
 golang.org/x/tools v0.0.0-20191029041327-9cc4af7d6b2c/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191029190741-b9c20aec41a5/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=

url.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"errors"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// ErrMissingComponent is thrown when the URL has empty or missing components
+var ErrMissingComponent = errors.New("missing URL component")
+
+// ErrTooManyComponent is thrown when there are more than 2 components
+var ErrTooManyComponent = errors.New("too many components")
+
+var timeRFC3339NoSec = "2006-01-02T15:04Z07:00"
+var timeFormats = []string{time.RFC3339, timeRFC3339NoSec}
+
+// Request is a parsed datetime URL
+type Request struct {
+	Time  time.Time
+	Zones []string
+}
+
+// ParseRequest parses an input URL into a Request
+func ParseRequest(u *url.URL) (Request, error) {
+	var err error
+
+	parts := strings.Split(u.Path, "/")[1:]
+	if len(parts) > 2 {
+		return Request{}, ErrTooManyComponent
+	}
+	if len(parts) < 1 {
+		return Request{}, ErrMissingComponent
+	}
+
+	// Parse time portion
+	var t time.Time
+	timeString := parts[0]
+	if len(timeString) == 0 {
+		return Request{}, ErrMissingComponent
+	}
+	for _, f := range timeFormats {
+		t, err = time.Parse(f, timeString)
+		if err == nil {
+			break
+		}
+	}
+	if err != nil {
+		return Request{}, err
+	}
+
+	// Split zones
+	var z []string
+	zoneString := ""
+	if len(parts) >= 2 {
+		zoneString = parts[1]
+	}
+	if len(zoneString) == 0 {
+		return Request{}, ErrMissingComponent
+	}
+	z = strings.Split(zoneString, ",")
+
+	return Request{
+		Time:  t,
+		Zones: z,
+	}, nil
+}

url_test.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"errors"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func mustURLParse(s string) *url.URL {
+	u, err := url.Parse(s)
+	if err != nil {
+		panic(err)
+	}
+	return u
+}
+
+func TestURLParse(t *testing.T) {
+	u := mustURLParse("http://test/2020-06-02T14:00+08:00/Singapore,Malaysia")
+	got, err := ParseRequest(u)
+	if err != nil {
+		t.Errorf("mismatch: got error %v", err)
+		return
+	}
+	want := Request{
+		time.Date(2020, 6, 2, 14, 0, 0, 0, time.FixedZone("UTC +8", 8*60*60)),
+		[]string{"Singapore", "Malaysia"},
+	}
+	if !cmp.Equal(got, want) {
+		t.Errorf("mismatch: \n%v", cmp.Diff(got, want))
+	}
+
+	u = mustURLParse("http://test/2019-04-30T18:00:00Z/Nowhere")
+	got, err = ParseRequest(u)
+	if err != nil {
+		t.Errorf("mismatch: got error %v", err)
+		return
+	}
+	want = Request{
+		time.Date(2019, 4, 30, 18, 0, 0, 0, time.FixedZone("UTC", 0)),
+		[]string{"Nowhere"},
+	}
+	if !cmp.Equal(got, want) {
+		t.Errorf("mismatch: \n%v", cmp.Diff(got, want))
+	}
+}
+
+func TestURLParseFail(t *testing.T) {
+	u := mustURLParse("http://test/2002-08-30T14:00+06:00/")
+	_, err := ParseRequest(u)
+	if !errors.Is(err, ErrMissingComponent) {
+		t.Errorf("mismatch: got error %v, want error %v", err, ErrMissingComponent)
+		return
+	}
+
+	u = mustURLParse("http://test/")
+	_, err = ParseRequest(u)
+	if !errors.Is(err, ErrMissingComponent) {
+		t.Errorf("mismatch: got error %v, want error %v", err, ErrMissingComponent)
+		return
+	}
+
+	u = mustURLParse("http://test/2000-01-13T00:00Z08:00/hi")
+	_, err = ParseRequest(u)
+	_, isParseError := err.(*time.ParseError)
+	if !isParseError {
+		t.Errorf("mismatch: got error %v, want time.ParseError", err)
+		return
+	}
+
+	u = mustURLParse("http://test/2000-01-13 00:00+08:00/hi")
+	_, err = ParseRequest(u)
+	_, isParseError = err.(*time.ParseError)
+	if !isParseError {
+		t.Errorf("mismatch: got error %v, want time.ParseError", err)
+		return
+	}
+
+}