added Complete() and Reopen() to Task.

example_test.go

@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package todotxt
+
+import (
+	"fmt"
+	"log"
+)
+
+func ExampleLoadFromFilename() {
+	if tasklist, err := LoadFromFilename("todo.txt"); err != nil {
+		log.Fatal(err)
+	} else {
+		fmt.Print(tasklist) // String representation of TaskList works as expected.
+	}
+
+	// Output:
+	// (A) Call Mom @Phone +Family
+	// (A) Schedule annual checkup +Health
+	// (B) Outline chapter 5 @Computer +Novel
+	// (C) Add cover sheets @Office +TPSReports
+	// Plan backyard herb garden @Home
+	// Pick up milk @GroceryStore
+	// Research self-publishing services @Computer +Novel
+	// x Download Todo.txt mobile app @Phone
+}
+
+func ExampleTaskList_LoadFromFilename() {
+	var tasklist TaskList
+
+	// This will overwrite whatever was in the tasklist before.
+	// Irrelevant here since the list is still empty.
+	if err := tasklist.LoadFromFilename("todo.txt"); err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(tasklist[0].Todo)      // Text part of first task (Call Mom)
+	fmt.Println(tasklist[2].Contexts)  // Slice of contexts from third task ([Computer])
+	fmt.Println(tasklist[3].Priority)  // Priority of fourth task (C)
+	fmt.Println(tasklist[7].Completed) // Completed flag of eigth task (true)
+	// Output:
+	// Call Mom
+	// [Computer]
+	// C
+	// true
+}

sort.go

@@ -35,7 +35,7 @@ func (tasklist *TaskList) Sort(sortFlag int) error {
 	case SORT_DUE_DATE_ASC, SORT_DUE_DATE_DESC:
 		tasklist.sortByDueDate(sortFlag)
 	default:
-		return errors.New("Unrecognized sort option")
+		return errors.New("unrecognized sort option")
 	}
 	return nil
 }
@@ -68,19 +68,17 @@ func (tasklist *TaskList) sortBy(by func(t1, t2 *Task) bool) *TaskList {
 
 func (tasklist *TaskList) sortByPriority(order int) *TaskList {
 	tasklist.sortBy(func(t1, t2 *Task) bool {
-		if order == SORT_PRIORITY_DESC { // DESC
+		if order == SORT_PRIORITY_ASC { // ASC
-			if t1.HasPriority() && t2.HasPriority() {
-				return t1.Priority > t2.Priority
-			} else {
-				return !t1.HasPriority()
-			}
-		} else { // ASC
 			if t1.HasPriority() && t2.HasPriority() {
 				return t1.Priority < t2.Priority
-			} else {
-				return t1.HasPriority()
 			}
+			return t1.HasPriority()
 		}
+		// DESC
+		if t1.HasPriority() && t2.HasPriority() {
+			return t1.Priority > t2.Priority
+		}
+		return !t1.HasPriority()
 	})
 	return tasklist
 }
@@ -89,16 +87,14 @@ func sortByDate(asc bool, hasDate1, hasDate2 bool, date1, date2 time.Time) bool
 	if asc { // ASC
 		if hasDate1 && hasDate2 {
 			return date1.Before(date2)
-		} else {
-			return hasDate2
-		}
-	} else { // DESC
-		if hasDate1 && hasDate2 {
-			return date1.After(date2)
-		} else {
-			return !hasDate2
 		}
+		return hasDate2
 	}
+	// DESC
+	if hasDate1 && hasDate2 {
+		return date1.After(date2)
+	}
+	return !hasDate2
 }
 
 func (tasklist *TaskList) sortByCreatedDate(order int) *TaskList {

sort_test.go

@@ -14,7 +14,9 @@ func TestTaskSortByPriority(t *testing.T) {
 
 	testTasklist = testTasklist[taskId : taskId+6]
 
-	testTasklist.Sort(SORT_PRIORITY_ASC)
+	if err := testTasklist.Sort(SORT_PRIORITY_ASC); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected = "(A) 2012-01-30 Call Mom @Call @Phone +Family"
 	testGot = testTasklist[0].Task()
@@ -52,7 +54,9 @@ func TestTaskSortByPriority(t *testing.T) {
 		t.Errorf("Expected Task[6] after Sort() to be [%s], but got [%s]", testExpected, testGot)
 	}
 
-	testTasklist.Sort(SORT_PRIORITY_DESC)
+	if err := testTasklist.Sort(SORT_PRIORITY_DESC); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected = "x 2014-01-03 Create golang library @Go +go-todotxt due:2014-01-05"
 	testGot = testTasklist[0].Task()
@@ -97,7 +101,9 @@ func TestTaskSortByCreatedDate(t *testing.T) {
 
 	testTasklist = testTasklist[taskId : taskId+5]
 
-	testTasklist.Sort(SORT_CREATED_DATE_ASC)
+	if err := testTasklist.Sort(SORT_CREATED_DATE_ASC); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected = "x 2014-01-03 Create golang library @Go +go-todotxt due:2014-01-05"
 	testGot = testTasklist[0].Task()
@@ -129,7 +135,9 @@ func TestTaskSortByCreatedDate(t *testing.T) {
 		t.Errorf("Expected Task[5] after Sort() to be [%s], but got [%s]", testExpected, testGot)
 	}
 
-	testTasklist.Sort(SORT_CREATED_DATE_DESC)
+	if err := testTasklist.Sort(SORT_CREATED_DATE_DESC); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected = "x (C) 2014-01-01 Create golang library documentation @Go +go-todotxt due:2014-01-12"
 	testGot = testTasklist[0].Task()
@@ -168,7 +176,9 @@ func TestTaskSortByCompletedDate(t *testing.T) {
 
 	testTasklist = testTasklist[taskId : taskId+6]
 
-	testTasklist.Sort(SORT_COMPLETED_DATE_ASC)
+	if err := testTasklist.Sort(SORT_COMPLETED_DATE_ASC); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected = "x Download Todo.txt mobile app @Phone"
 	testGot = testTasklist[0].Task()
@@ -206,7 +216,9 @@ func TestTaskSortByCompletedDate(t *testing.T) {
 		t.Errorf("Expected Task[6] after Sort() to be [%s], but got [%s]", testExpected, testGot)
 	}
 
-	testTasklist.Sort(SORT_COMPLETED_DATE_DESC)
+	if err := testTasklist.Sort(SORT_COMPLETED_DATE_DESC); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected = "x 2014-01-04 2014-01-01 Create some more golang library test cases @Go +go-todotxt"
 	testGot = testTasklist[0].Task()
@@ -251,7 +263,9 @@ func TestTaskSortByDueDate(t *testing.T) {
 
 	testTasklist = testTasklist[taskId : taskId+4]
 
-	testTasklist.Sort(SORT_DUE_DATE_ASC)
+	if err := testTasklist.Sort(SORT_DUE_DATE_ASC); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected = "x 2014-01-02 (B) 2013-12-30 Create golang library test cases @Go +go-todotxt"
 	testGot = testTasklist[0].Task()
@@ -277,7 +291,9 @@ func TestTaskSortByDueDate(t *testing.T) {
 		t.Errorf("Expected Task[4] after Sort() to be [%s], but got [%s]", testExpected, testGot)
 	}
 
-	testTasklist.Sort(SORT_DUE_DATE_DESC)
+	if err := testTasklist.Sort(SORT_DUE_DATE_DESC); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected = "(B) 2013-12-01 Outline chapter 5 @Computer +Novel Level:5 private:false due:2014-02-17"
 	testGot = testTasklist[0].Task()
@@ -303,3 +319,13 @@ func TestTaskSortByDueDate(t *testing.T) {
 		t.Errorf("Expected Task[4] after Sort() to be [%s], but got [%s]", testExpected, testGot)
 	}
 }
+
+func TestTaskSortError(t *testing.T) {
+	testTasklist.LoadFromFilename(testInputSort)
+
+	if err := testTasklist.Sort(123); err == nil {
+		t.Errorf("Expected Sort() to fail because of unrecognized sort option, but it didn't!")
+	} else if err.Error() != "unrecognized sort option" {
+		t.Error(err)
+	}
+}

task.go

@@ -67,7 +67,7 @@ func (task Task) String() string {
 	if len(task.AdditionalTags) > 0 {
 		// Sort map alphabetically by keys
 		keys := make([]string, 0, len(task.AdditionalTags))
-		for key, _ := range task.AdditionalTags {
+		for key := range task.AdditionalTags {
 			keys = append(keys, key)
 		}
 		sort.Strings(keys)
@@ -106,7 +106,25 @@ func (task *Task) HasDueDate() bool {
 
 // HasCompletedDate returns true if the task has a completed date.
 func (task *Task) HasCompletedDate() bool {
-	return !task.CompletedDate.IsZero()
+	return !task.CompletedDate.IsZero() && task.Completed
+}
+
+// Complete sets Task.Completed to 'true' if the task was not already completed.
+// Also sets Task.CompletedDate to time.Now()
+func (task *Task) Complete() {
+	if !task.Completed {
+		task.Completed = true
+		task.CompletedDate = time.Now()
+	}
+}
+
+// Reopen sets Task.Completed to 'false' if the task was completed.
+// Also resets Task.CompletedDate.
+func (task *Task) Reopen() {
+	if task.Completed {
+		task.Completed = false
+		task.CompletedDate = time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC) // time.IsZero() value
+	}
 }
 
 // IsOverdue returns true if due date is in the past.
@@ -116,9 +134,8 @@ func (task *Task) HasCompletedDate() bool {
 func (task *Task) IsOverdue() bool {
 	if task.HasDueDate() {
 		return task.DueDate.Before(time.Now())
-	} else {
-		return false
 	}
+	return false
 }
 
 // Due returns the duration passed since due date, or until due date from now.
@@ -129,7 +146,6 @@ func (task *Task) IsOverdue() bool {
 func (task *Task) Due() time.Duration {
 	if task.IsOverdue() {
 		return time.Now().Sub(task.DueDate)
-	} else {
-		return task.DueDate.Sub(time.Now())
 	}
+	return task.DueDate.Sub(time.Now())
 }

task_test.go

@@ -263,21 +263,21 @@ func TestTaskCompleted(t *testing.T) {
 	testExpected = true
 	testGot = testTasklist[taskId-1].Completed
 	if testGot != testExpected {
-		t.Errorf("Expected Task[%d] not to be completed, but got '%v'", taskId, testGot)
+		t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
 	}
 	taskId++
 
 	testExpected = true
 	testGot = testTasklist[taskId-1].Completed
 	if testGot != testExpected {
-		t.Errorf("Expected Task[%d] not to be completed, but got '%v'", taskId, testGot)
+		t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
 	}
 	taskId++
 
 	testExpected = true
 	testGot = testTasklist[taskId-1].Completed
 	if testGot != testExpected {
-		t.Errorf("Expected Task[%d] not to be completed, but got '%v'", taskId, testGot)
+		t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
 	}
 	taskId++
 
@@ -379,6 +379,145 @@ func TestTaskIsOverdue(t *testing.T) {
 		t.Errorf("Expected Task[%d] to be due since 72 hours, but got '%v'", taskId, testGot)
 	}
 	taskId++
+
+	testGot = testTasklist[taskId-1].IsOverdue()
+	if testGot.(bool) {
+		t.Errorf("Expected Task[%d] not to be overdue, but got '%v'", taskId, testGot)
+	}
+	taskId++
+}
+
+func TestTaskComplete(t *testing.T) {
+	testTasklist.LoadFromFilename(testInputTask)
+	taskId := 44
+
+	// first 4 tasks should all match the same tests
+	for i := 0; i < 4; i++ {
+		testExpected = false
+		testGot = testTasklist[taskId-1].Completed
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] not to be completed, but got '%v'", taskId, testGot)
+		}
+		testGot = testTasklist[taskId-1].HasCompletedDate()
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] not to have a completed date, but got '%v'", taskId, testGot)
+		}
+		testTasklist[taskId-1].Complete()
+		testExpected = true
+		testGot = testTasklist[taskId-1].Completed
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
+		}
+		testGot = testTasklist[taskId-1].HasCompletedDate()
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to have a completed date, but got '%v'", taskId, testGot)
+		}
+		testExpected = time.Now().Format(DateLayout)
+		testGot = testTasklist[taskId-1].CompletedDate.Format(DateLayout)
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to have a completed date of '%v', but got '%v'", taskId, testExpected, testGot)
+		}
+		taskId++
+	}
+
+	testExpected = true
+	testGot = testTasklist[taskId-1].Completed
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
+	}
+	testGot = testTasklist[taskId-1].HasCompletedDate()
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to have a completed date, but got '%v'", taskId, testGot)
+	}
+	testTasklist[taskId-1].Complete()
+	testGot = testTasklist[taskId-1].Completed // should be unchanged
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
+	}
+	testGot = testTasklist[taskId-1].HasCompletedDate() // should be unchanged
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to have a completed date, but got '%v'", taskId, testGot)
+	}
+	testExpected = "2012-01-01" // should be unchanged
+	testGot = testTasklist[taskId-1].CompletedDate.Format(DateLayout)
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to have a completed date of '%v', but got '%v'", taskId, testExpected, testGot)
+	}
+	taskId++
+}
+
+func TestTaskReopen(t *testing.T) {
+	testTasklist.LoadFromFilename(testInputTask)
+	taskId := 49
+
+	// the first 2 tasks should match the same tests
+	for i := 0; i < 2; i++ {
+		testExpected = true
+		testGot = testTasklist[taskId-1].Completed
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
+		}
+		testExpected = false
+		testGot = testTasklist[taskId-1].HasCompletedDate()
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to have a completed date, but got '%v'", taskId, testGot)
+		}
+		testTasklist[taskId-1].Reopen()
+		testExpected = false
+		testGot = testTasklist[taskId-1].Completed
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to not be completed, but got '%v'", taskId, testGot)
+		}
+		testGot = testTasklist[taskId-1].HasCompletedDate()
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to not have a completed date, but got '%v'", taskId, testGot)
+		}
+		taskId++
+	}
+
+	// the next 3 tasks should all match the same tests
+	for i := 0; i < 3; i++ {
+		testExpected = true
+		testGot = testTasklist[taskId-1].Completed
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
+		}
+		testGot = testTasklist[taskId-1].HasCompletedDate()
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to have a completed date, but got '%v'", taskId, testGot)
+		}
+		testTasklist[taskId-1].Reopen()
+		testExpected = false
+		testGot = testTasklist[taskId-1].Completed
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to not be completed, but got '%v'", taskId, testGot)
+		}
+		testGot = testTasklist[taskId-1].HasCompletedDate()
+		if testGot != testExpected {
+			t.Errorf("Expected Task[%d] to not have a completed date, but got '%v'", taskId, testGot)
+		}
+		taskId++
+	}
+
+	testExpected = false
+	testGot = testTasklist[taskId-1].Completed
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
+	}
+	testGot = testTasklist[taskId-1].HasCompletedDate()
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to have a completed date, but got '%v'", taskId, testGot)
+	}
+	testTasklist[taskId-1].Reopen()
+	testGot = testTasklist[taskId-1].Completed // should be unchanged
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to be completed, but got '%v'", taskId, testGot)
+	}
+	testGot = testTasklist[taskId-1].HasCompletedDate() // should be unchanged
+	if testGot != testExpected {
+		t.Errorf("Expected Task[%d] to have a completed date, but got '%v'", taskId, testGot)
+	}
+	taskId++
 }
 
 func compareSlices(list1 []string, list2 []string) bool {

testdata/task_todo.txt

@@ -59,3 +59,20 @@ x 2014-01-03 2014-01-01 Create some more golang library test cases @Go +go-todot
 x 2014-01-04 (B) 2013-12-30 Create golang library @Go +go-todotxt due:2014-01-02
 (B) 2013-12-01 private:false Outline chapter 5 +Novel @Computer due:2017-07-17 Level:5 
 Research self-publishing services +Novel +Novel +Novel due:2014-01-01
+x 2014-01-03 2014-01-01 Create some more golang library test cases @Go +go-todotxt
+
+# Complete test cases
+Create golang library @Go +go-todotxt due:2014-01-05
+(A) @Phone Call Mom @Call +Family
+2014-01-03 Create golang library @Go +go-todotxt due:2014-01-05
+(B) 2013-12-30 Create golang library test cases @Go +go-todotxt
+x 2012-01-01 More Go!
+
+# Reopen test cases
+x Download Todo.txt mobile app @Phone
+x (C) 2014-01-01 Create golang library documentation @Go +go-todotxt due:2014-01-12
+x 2014-01-03 Create golang library @Go +go-todotxt due:2014-01-05
+x 2014-01-02 (B) 2013-12-30 Create golang library test cases @Go +go-todotxt
+x 2014-01-03 2014-01-01 Create some more golang library test cases @Go +go-todotxt
+(B) 2013-12-30 Create golang library test cases @Go +go-todotxt
+

testdata/tasklist_completedDate_error.txt

@@ -0,0 +1,6 @@
+x (C) 2014-01-01 Create golang library documentation @Go +go-todotxt due:2014-01-12
+x Download Todo.txt mobile app @Phone
+x 2014-01-03 Create golang library @Go +go-todotxt due:2014-01-05
+x (C) 2014-01-01 Create golang library documentation @Go +go-todotxt due:2014-01-12
+x 2014-01-02 (B) 2013-12-30 Create golang library test cases @Go +go-todotxt
+x 2014-25-04 2014-01-01 Create some more golang library test cases @Go +go-todotxt

testdata/tasklist_createdDate_error.txt

@@ -0,0 +1,5 @@
+2013-02-22 Pick up milk @GroceryStore
+x Download Todo.txt mobile app @Phone    
+(B) 2013-13-01 private:false Outline chapter 5 +Novel @Computer Level:5 due:2014-02-17
+x 2014-01-02 (B) 2013-12-30 Create golang library test cases @Go +go-todotxt
+x 2014-01-03 2014-01-01 Create some more golang library test cases @Go +go-todotxt

testdata/tasklist_dueDate_error.txt

@@ -0,0 +1,5 @@
+B) 2013-12-01 private:false Outline chapter 5 +Novel @Computer Level:5 due:2014-02-17
+x 2014-01-02 (B) 2013-12-30 Create golang library test cases @Go +go-todotxt
+x 2014-01-03 2014-01-01 Create some more golang library test cases @Go +go-todotxt
+(B) 2013-12-01 private:false Outline chapter 5 +Novel @Computer Level:5 due:2014-02-32
+x (C) 2014-01-01 Create golang library documentation @Go +go-todotxt due:2014-01-12

todotxt.go

@@ -23,12 +23,13 @@ import (
 // It is usually loaded from a whole todo.txt file.
 type TaskList []Task
 
-// IgnoreComments can be set to 'false', in order to revert to more standard todo.txt behaviour.
+// IgnoreComments can be set to 'false', in order to revert to a more standard todo.txt behaviour.
 // The todo.txt format does not define comments.
 var (
-	// Used for formatting time.Time into todo.txt date format and vice-versa.
+	// DateLayout is used for formatting time.Time into todo.txt date format and vice-versa.
 	DateLayout = "2006-01-02"
-	// Ignores comments (Lines/Text starting with "#").
+	// IgnoreComments is used to switch ignoring of comments (lines starting with "#").
+	// If this is set to 'false', then lines starting with "#" will be parsed as tasks.
 	IgnoreComments = true
 
 	// unexported vars
@@ -74,10 +75,10 @@ func (tasklist *TaskList) LoadFromFile(file *os.File) error {
 			task.Completed = true
 			// Check for completed date
 			if completedDateRx.MatchString(task.Original) {
-				if date, err := time.Parse(DateLayout, completedDateRx.FindStringSubmatch(task.Original)[1]); err != nil {
+				if date, err := time.Parse(DateLayout, completedDateRx.FindStringSubmatch(task.Original)[1]); err == nil {
-					return err
-				} else {
 					task.CompletedDate = date
+				} else {
+					return err
 				}
 			}
 
@@ -94,11 +95,11 @@ func (tasklist *TaskList) LoadFromFile(file *os.File) error {
 
 		// Check for created date
 		if createdDateRx.MatchString(task.Original) {
-			if date, err := time.Parse(DateLayout, createdDateRx.FindStringSubmatch(task.Original)[2]); err != nil {
+			if date, err := time.Parse(DateLayout, createdDateRx.FindStringSubmatch(task.Original)[2]); err == nil {
-				return err
-			} else {
 				task.CreatedDate = date
 				task.Todo = createdDateRx.ReplaceAllString(task.Todo, "") // Remove from Todo text
+			} else {
+				return err
 			}
 		}
 
@@ -137,10 +138,10 @@ func (tasklist *TaskList) LoadFromFile(file *os.File) error {
 			for _, match := range matches {
 				key, value := match[2], match[3]
 				if key == "due" { // due date is a known addon tag, it has its own struct field
-					if date, err := time.Parse(DateLayout, value); err != nil {
+					if date, err := time.Parse(DateLayout, value); err == nil {
-						return err
-					} else {
 						task.DueDate = date
+					} else {
+						return err
 					}
 				} else if key != "" && value != "" {
 					tags[key] = value
@@ -195,8 +196,10 @@ func (tasklist *TaskList) WriteToFilename(filename string) error {
 // Using *os.File instead of a filename allows to also use os.Stdin.
 func LoadFromFile(file *os.File) (TaskList, error) {
 	tasklist := TaskList{}
-	err := tasklist.LoadFromFile(file)
+	if err := tasklist.LoadFromFile(file); err != nil {
-	return tasklist, err
+		return nil, err
+	}
+	return tasklist, nil
 }
 
 // WriteToFile writes a TaskList to *os.File.
@@ -209,8 +212,10 @@ func WriteToFile(tasklist *TaskList, file *os.File) error {
 // LoadFromFilename loads and returns a TaskList from a file (most likely called "todo.txt").
 func LoadFromFilename(filename string) (TaskList, error) {
 	tasklist := TaskList{}
-	err := tasklist.LoadFromFilename(filename)
+	if err := tasklist.LoadFromFilename(filename); err != nil {
-	return tasklist, err
+		return nil, err
+	}
+	return tasklist, nil
 }
 
 // WriteToFilename writes a TaskList to the specified file (most likely called "todo.txt").

todotxt_test.go

@@ -11,12 +11,16 @@ import (
 )
 
 var (
-	testInputTasklist  = "testdata/tasklist_todo.txt"
+	testInputTasklist                   = "testdata/tasklist_todo.txt"
-	testOutput         = "testdata/ouput_todo.txt"
+	testInputTasklistCreatedDateError   = "testdata/tasklist_createdDate_error.txt"
-	testExpectedOutput = "testdata/expected_todo.txt"
+	testInputTasklistDueDateError       = "testdata/tasklist_dueDate_error.txt"
-	testTasklist       TaskList
+	testInputTasklistCompletedDateError = "testdata/tasklist_completedDate_error.txt"
-	testExpected       interface{}
+	testInputTasklistScannerError       = "testdata/tasklist_scanner_error.txt"
-	testGot            interface{}
+	testOutput                          = "testdata/ouput_todo.txt"
+	testExpectedOutput                  = "testdata/expected_todo.txt"
+	testTasklist                        TaskList
+	testExpected                        interface{}
+	testGot                             interface{}
 )
 
 func TestLoadFromFile(t *testing.T) {
@@ -39,6 +43,10 @@ func TestLoadFromFile(t *testing.T) {
 			t.Errorf("Expected TaskList to be [%s], but got [%s]", testExpected, testGot)
 		}
 	}
+
+	if testTasklist, err := LoadFromFile(nil); testTasklist != nil || err == nil {
+		t.Errorf("Expected LoadFromFile to fail, but got TaskList back: [%s]", testTasklist)
+	}
 }
 
 func TestLoadFromFilename(t *testing.T) {
@@ -55,6 +63,10 @@ func TestLoadFromFilename(t *testing.T) {
 			t.Errorf("Expected TaskList to be [%s], but got [%s]", testExpected, testGot)
 		}
 	}
+
+	if testTasklist, err := LoadFromFilename("some_file_that_does_not_exists.txt"); testTasklist != nil || err == nil {
+		t.Errorf("Expected LoadFromFilename to fail, but got TaskList back: [%s]", testTasklist)
+	}
 }
 
 func TestWriteFile(t *testing.T) {
@@ -192,7 +204,9 @@ func TestTaskListWriteFilename(t *testing.T) {
 }
 
 func TestTaskListCount(t *testing.T) {
-	testTasklist.LoadFromFilename(testInputTasklist)
+	if err := testTasklist.LoadFromFilename(testInputTasklist); err != nil {
+		t.Fatal(err)
+	}
 
 	testExpected := 63
 	testGot := len(testTasklist)
@@ -200,3 +214,30 @@ func TestTaskListCount(t *testing.T) {
 		t.Errorf("Expected TaskList to contain %d tasks, but got %d", testExpected, testGot)
 	}
 }
+
+func TestTaskListReadErrors(t *testing.T) {
+	if testTasklist, err := LoadFromFilename(testInputTasklistCreatedDateError); testTasklist != nil || err == nil {
+		t.Errorf("Expected LoadFromFilename to fail because of invalid created date, but got TaskList back: [%s]", testTasklist)
+	} else if err.Error() != `parsing time "2013-13-01": month out of range` {
+		t.Error(err)
+	}
+
+	if testTasklist, err := LoadFromFilename(testInputTasklistDueDateError); testTasklist != nil || err == nil {
+		t.Errorf("Expected LoadFromFilename to fail because of invalid due date, but got TaskList back: [%s]", testTasklist)
+	} else if err.Error() != `parsing time "2014-02-32": day out of range` {
+		t.Error(err)
+	}
+
+	if testTasklist, err := LoadFromFilename(testInputTasklistCompletedDateError); testTasklist != nil || err == nil {
+		t.Errorf("Expected LoadFromFilename to fail because of invalid completed date, but got TaskList back: [%s]", testTasklist)
+	} else if err.Error() != `parsing time "2014-25-04": month out of range` {
+		t.Error(err)
+	}
+
+	// really silly test
+	if testTasklist, err := LoadFromFilename(testInputTasklistScannerError); testTasklist != nil || err == nil {
+		t.Errorf("Expected LoadFromFilename to fail because of invalid file, but got TaskList back: [%s]", testTasklist)
+	} else if err.Error() != `bufio.Scanner: token too long` {
+		t.Error(err)
+	}
+}