Add unit testing and better error catching

Author: Ross

main.go

@@ -33,7 +33,7 @@ var opts struct {
 	MaxObjects int64  `short:"m" long:"max" description:"maximum number of s3 object to list" default:"1000" env:"TAG_MONGER_MAX"`
 	Bucket     string `short:"b" long:"bucket" description:"name of s3 bucket" required:"true" env:"TAG_MONGER_BUCKET"`
 	Days       int    `short:"d" long:"days" description:"Expire tags older than N days" default:"14" env:"TAG_MONGER_DAYS"`
-	Weeks       int    `short:"w" long:"weeks" description:"Expire weekly tags older than N weeks" default:"12" env:"TAG_MONGER_WEEKS"`
+	Weeks       int    `short:"w" long:"weeks" description:"Expire weekly tags older than N weeks" default:"14" env:"TAG_MONGER_WEEKS"`
 	Noop       bool   `short:"n" long:"noop" description:"Do not make any changes" env:"TAG_MONGER_NOOP"`
 	Group      struct {
 		Help bool `short:"h" long:"help" description:"Show this help message"`
@@ -49,6 +49,31 @@ func bod(t time.Time) time.Time {
 func parse_d_tag(tag string) (t time.Time, err error) {
 	const shortForm = "d_2006_01_02"
 
+	parts := strings.Split(tag, "_")
+	if len(parts) != 4{
+		return time.Time{}, fmt.Errorf("Got invalid format")
+	}
+	if strings.ToLower(parts[0]) != "d" {
+		return time.Time{}, fmt.Errorf("Got the wrong tag, should be a daily, got %s",parts[0])
+	}
+	month, err := strconv.Atoi((parts[2]))
+	if err != nil{
+		return time.Time{}, err
+	}
+	day, err := strconv.Atoi((parts[3]))
+	if err != nil{
+		return time.Time{}, err
+	}
+	if len(parts[1]) != 4 {
+		return time.Time{}, fmt.Errorf("Got the wrong year format, got %s",parts[1])
+	}
+	if len(parts[2]) != 2 || month >12 || month<01{
+		return time.Time{}, fmt.Errorf("Got the wrong month format, got %s",parts[2])
+	}
+	if len(parts[3]) != 2 || day >31 || day <01{
+		return time.Time{}, fmt.Errorf("Got the wrong day format, got %s",parts[2])
+	}
+
 	t, err = time.Parse(shortForm, tag)
 	return t, err
 }
@@ -58,6 +83,15 @@ func parse_w_tag(tag string) (t time.Time, err error) {
 	if len(parts) != 3{
 		return time.Time{}, err
 	}
+	if strings.ToLower(parts[0]) != "w" {
+		return time.Time{}, fmt.Errorf("Got the wrong tag, should be a weekly, got %s",parts[0])
+	}
+	if len(parts[1]) != 4 {
+		return time.Time{}, fmt.Errorf("Got the wrong year format, got %s",parts[1])
+	}
+	if len(parts[2]) != 2 {
+		return time.Time{}, fmt.Errorf("Got the wrong week format, got %s",parts[2])
+	}
 	year, err := strconv.Atoi((parts[1]))
 	if err != nil {
 		return time.Time{}, err
@@ -66,9 +100,12 @@ func parse_w_tag(tag string) (t time.Time, err error) {
 	if err != nil {
 		return time.Time{}, err
 	}
+	if week >=53 || week <=0 {
+		return time.Time{}, fmt.Errorf("invalid week")
+	}
 	// ISO week date format
 	// Get time for first day of the given year and week
-  t = time.Date(year, 0, 0, 0, 0, 0, 0, time.UTC)
+  t = time.Date(year, 1, 0, 0, 0, 0, 0, time.UTC)
   t = t.AddDate(0, 0, (week-1)*7+1)
   return t, nil
 }
@@ -259,7 +296,7 @@ func run() error {
 	w_fresh_objs,w_expired_objs,w_retired_objs,err := parse_objects(
 		weekly_taglike_objs,
 		"America/Los_Angeles",
-		opts.Weeks)
+		opts.Weeks*7)
 	if err != nil {
 		return err
 	}

main_test.go

@@ -0,0 +1,144 @@
+package main
+
+import (
+	"testing"
+	"time"
+)
+
+func TestDailyParser(t *testing.T){
+	tests := []struct{
+		name string
+		tag string
+		expected time.Time
+		wantErr bool
+	}{
+		{
+			name: "valid begining of the year tag",
+			tag: "d_2024_01_01",
+			expected: time.Date(2024,1,1,0,0,0,0,time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "valid may 21 2025",
+			tag: "d_2025_05_21",
+			expected: time.Date(2025,5,21,0,0,0,0,time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "invalid daily",
+			tag: "d_2025_05",
+			wantErr: true,
+		},
+		{
+			name: "invalid daily, impossible day format",
+			tag: "d_2025_05_32",
+			wantErr: true,
+		},
+		{
+			name: "invalid daily, bad date format",
+			tag: "d_2025_05_3232",
+			wantErr: true,
+		},
+		{
+			name: "invalid daily, impossible month",
+			tag: "d_2025_14_30",
+			wantErr: true,
+		},
+		{
+			name: "invalid daily, bad year format",
+			tag: "d_225_05_09",
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T){
+			got, err := parse_d_tag(tt.tag)
+			if (err != nil) != tt.wantErr{
+				t.Errorf("parse_d_tag(%s) got %v, want %v. Error: %s",tt.tag, got, tt.expected, err)
+			}
+			if !tt.wantErr && !got.Equal(tt.expected){
+				t.Errorf("parse_d_tag(%s) = %v, want %v",tt.tag, got, tt.expected)
+			}
+		})
+	}
+
+}
+
+func TestWeeklyParser(t *testing.T) {
+	tests := []struct{
+		name string
+		tag string
+		expected time.Time
+		wantErr bool
+	}{
+		{
+			name: "valid begining of the year tag",
+			tag: "W_2024_01",
+			expected: time.Date(2024,1,1,0,0,0,0,time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "valid may 21 2025",
+			tag: "w_2025_21",
+			expected: time.Date(2025,5,21,0,0,0,0,time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "valid Jan 29 2025",
+			tag: "w_2025_05",
+			expected: time.Date(2025,1,29,0,0,0,0,time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "valid tag",
+			tag: "W_2024_12",
+			expected: time.Date(2024,3,18,0,0,0,0,time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "valid ending of the year tag",
+			tag: "W_2024_52",
+			expected: time.Date(2024,12,23,0,0,0,0,time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "valid 12/24/2025 tag",
+			tag: "W_2025_52",
+			expected: time.Date(2025,12,24,0,0,0,0,time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "invalid tag",
+			tag: "W_2025_df",
+			wantErr: true,
+		},
+		{
+			name: "invalid tag wrong year format",
+			tag: "W_205_01",
+			wantErr: true,
+		},
+		{
+			name: "invalid tag wrong week format",
+			tag: "W_2025_1",
+			wantErr: true,
+		},
+		{
+			name: "invalid tag impossible week",
+			tag: "W_2025_54",
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T){
+			got, err := parse_w_tag(tt.tag)
+			if (err != nil) != tt.wantErr{
+				t.Errorf("parse_w_tag(%s) error = %v, want %v. ",tt.tag, got, tt.expected)
+			}
+			if !tt.wantErr && !got.Equal(tt.expected){
+				t.Errorf("parse_w_tag(%s) = %v, want %v",tt.tag, got, tt.expected)
+			}
+		})
+	}
+
+}