fix(datepicker): validate that input actually parses (#5711)

* fix(datepicker): throw when value is set to invalid type

BREAKING CHANGE: You must now use an actual Date object rather than a
string when setting the value of the datepicker programmatically
(through value, ngModel, or formControl).

* addressed comments

* validate that datepicker input parses

* tweak handling of invalid dates.

* fix tests

* address feedback

* make sure datepicker selected date is valid

* rework validation again

* addressed comments

* fix lint

src/demo-app/datepicker/datepicker-demo.html

@@ -40,6 +40,9 @@
            placeholder="Pick a date"
            (dateInput)="onDateInput($event)"
            (dateChange)="onDateChange($event)">
+    <md-error *ngIf="resultPickerModel.hasError('mdDatepickerParse')">
+      "{{resultPickerModel.getError('mdDatepickerParse').text}}" is not a valid date!
+    </md-error>
     <md-error *ngIf="resultPickerModel.hasError('mdDatepickerMin')">Too early!</md-error>
     <md-error *ngIf="resultPickerModel.hasError('mdDatepickerMax')">Too late!</md-error>
     <md-error *ngIf="resultPickerModel.hasError('mdDatepickerFilter')">Date unavailable!</md-error>

src/lib/core/datetime/date-adapter.ts

@@ -107,15 +107,15 @@ export abstract class DateAdapter<D> {
    * @param value The value to parse.
    * @param parseFormat The expected format of the value being parsed
    *     (type is implementation-dependent).
-   * @returns The parsed date, or null if date could not be parsed.
+   * @returns The parsed date.
    */
   abstract parse(value: any, parseFormat: any): D | null;
 
   /**
    * Formats a date as a string.
-   * @param date The value to parse.
+   * @param date The value to format.
    * @param displayFormat The format to use to display the date as a string.
-   * @returns The parsed date, or null if date could not be parsed.
+   * @returns The formatted date string.
    */
   abstract format(date: D, displayFormat: any): string;
 
@@ -156,6 +156,20 @@ export abstract class DateAdapter<D> {
    */
   abstract getISODateString(date: D): string;
 
+  /**
+   * Checks whether the given object is considered a date instance by this DateAdapter.
+   * @param obj The object to check
+   * @returns Whether the object is a date instance.
+   */
+  abstract isDateInstance(obj: any): boolean;
+
+  /**
+   * Checks whether the given date is valid.
+   * @param date The date to check.
+   * @returns Whether the date is valid.
+   */
+  abstract isValid(date: D): boolean;
+
   /**
    * Sets the locale used for all dates.
    * @param locale The new locale.

src/lib/core/datetime/native-date-adapter.spec.ts

@@ -196,8 +196,13 @@ describe('NativeDateAdapter', () => {
     expect(adapter.parse(date)).not.toBe(date);
   });
 
-  it('should parse invalid value as null', () => {
-    expect(adapter.parse('hello')).toBeNull();
+  it('should parse invalid value as invalid', () => {
+    let d = adapter.parse('hello');
+    expect(d).not.toBeNull();
+    expect(adapter.isDateInstance(d))
+        .toBe(true, 'Expected string to have been fed through Date.parse');
+    expect(adapter.isValid(d as Date))
+        .toBe(false, 'Expected to parse as "invalid date" object');
   });
 
   it('should format', () => {
@@ -238,6 +243,11 @@ describe('NativeDateAdapter', () => {
     }
   });
 
+  it('should throw when attempting to format invalid date', () => {
+    expect(() => adapter.format(new Date(NaN), {}))
+        .toThrowError(/NativeDateAdapter: Cannot format invalid date\./);
+  });
+
   it('should add years', () => {
     expect(adapter.addCalendarYears(new Date(2017, JAN, 1), 1)).toEqual(new Date(2018, JAN, 1));
     expect(adapter.addCalendarYears(new Date(2017, JAN, 1), -1)).toEqual(new Date(2016, JAN, 1));
@@ -304,6 +314,23 @@ describe('NativeDateAdapter', () => {
       expect(adapter.format(new Date(1800, 7, 14), {day: 'numeric'})).toBe('Thu Aug 14 1800');
     }
   });
+
+  it('should count today as a valid date instance', () => {
+    let d = new Date();
+    expect(adapter.isValid(d)).toBe(true);
+    expect(adapter.isDateInstance(d)).toBe(true);
+  });
+
+  it('should count an invalid date as an invalid date instance', () => {
+    let d = new Date(NaN);
+    expect(adapter.isValid(d)).toBe(false);
+    expect(adapter.isDateInstance(d)).toBe(true);
+  });
+
+  it('should count a string as not a date instance', () => {
+    let d = '1/1/2017';
+    expect(adapter.isDateInstance(d)).toBe(false);
+  });
 });
 
 

src/lib/core/datetime/native-date-adapter.ts

@@ -157,11 +157,16 @@ export class NativeDateAdapter extends DateAdapter<Date> {
   parse(value: any): Date | null {
     // We have no way using the native JS Date to set the parse format or locale, so we ignore these
     // parameters.
-    let timestamp = typeof value == 'number' ? value : Date.parse(value);
-    return isNaN(timestamp) ? null : new Date(timestamp);
+    if (typeof value == 'number') {
+      return new Date(value);
+    }
+    return value ? new Date(Date.parse(value)) : null;
   }
 
   format(date: Date, displayFormat: Object): string {
+    if (!this.isValid(date)) {
+      throw Error('NativeDateAdapter: Cannot format invalid date.');
+    }
     if (SUPPORTS_INTL_API) {
       if (this.useUtcForDisplay) {
         date = new Date(Date.UTC(
@@ -207,6 +212,14 @@ export class NativeDateAdapter extends DateAdapter<Date> {
     ].join('-');
   }
 
+  isDateInstance(obj: any) {
+    return obj instanceof Date;
+  }
+
+  isValid(date: Date) {
+    return !isNaN(date.getTime());
+  }
+
   /** Creates a date but allows the month and date to overflow. */
   private _createDateWithOverflow(year: number, month: number, date: number) {
     let result = new Date(year, month, date);

src/lib/datepicker/calendar.ts

@@ -66,13 +66,13 @@ export class MdCalendar<D> implements AfterContentInit, OnDestroy {
   @Input() startView: 'month' | 'year' = 'month';
 
   /** The currently selected date. */
-  @Input() selected: D;
+  @Input() selected: D | null;
 
   /** The minimum selectable date. */
-  @Input() minDate: D;
+  @Input() minDate: D | null;
 
   /** The maximum selectable date. */
-  @Input() maxDate: D;
+  @Input() maxDate: D | null;
 
   /** A function used to filter which dates are selectable. */
   @Input() dateFilter: (date: D) => boolean;

src/lib/datepicker/datepicker-input.ts

@@ -112,36 +112,41 @@ export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAcces
   /** The value of the input. */
   @Input()
   get value(): D | null {
-    return this._dateAdapter.parse(this._elementRef.nativeElement.value,
-        this._dateFormats.parse.dateInput);
+    return this._getValidDateOrNull(this._dateAdapter.parse(
+        this._elementRef.nativeElement.value, this._dateFormats.parse.dateInput));
   }
   set value(value: D | null) {
-    let date = this._dateAdapter.parse(value, this._dateFormats.parse.dateInput);
+    if (value != null && !this._dateAdapter.isDateInstance(value)) {
+      throw Error('Datepicker: value not recognized as a date object by DateAdapter.');
+    }
+    this._lastValueValid = !value || this._dateAdapter.isValid(value);
+    value = this._getValidDateOrNull(value);
+
     let oldDate = this.value;
     this._renderer.setProperty(this._elementRef.nativeElement, 'value',
-        date ? this._dateAdapter.format(date, this._dateFormats.display.dateInput) : '');
-    if (!this._dateAdapter.sameDate(oldDate, date)) {
-      this._valueChange.emit(date);
+        value ? this._dateAdapter.format(value, this._dateFormats.display.dateInput) : '');
+    if (!this._dateAdapter.sameDate(oldDate, value)) {
+      this._valueChange.emit(value);
     }
   }
 
   /** The minimum valid date. */
   @Input()
-  get min(): D { return this._min; }
-  set min(value: D) {
+  get min(): D | null { return this._min; }
+  set min(value: D | null) {
     this._min = value;
     this._validatorOnChange();
   }
-  private _min: D;
+  private _min: D | null;
 
   /** The maximum valid date. */
   @Input()
-  get max(): D { return this._max; }
-  set max(value: D) {
+  get max(): D | null { return this._max; }
+  set max(value: D | null) {
     this._max = value;
     this._validatorOnChange();
   }
-  private _max: D;
+  private _max: D | null;
 
   /** Whether the datepicker-input is disabled. */
   @Input()
@@ -168,6 +173,12 @@ export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAcces
 
   private _datepickerSubscription: Subscription;
 
+  /** The form control validator for whether the input parses. */
+  private _parseValidator: ValidatorFn = (): ValidationErrors | null => {
+    return this._lastValueValid ?
+        null : {'mdDatepickerParse': {'text': this._elementRef.nativeElement.value}};
+  }
+
   /** The form control validator for the min date. */
   private _minValidator: ValidatorFn = (control: AbstractControl): ValidationErrors | null => {
     return (!this.min || !control.value ||
@@ -190,7 +201,11 @@ export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAcces
 
   /** The combined form control validator for this input. */
   private _validator: ValidatorFn | null =
-      Validators.compose([this._minValidator, this._maxValidator, this._filterValidator]);
+      Validators.compose(
+          [this._parseValidator, this._minValidator, this._maxValidator, this._filterValidator]);
+
+  /** Whether the last value set on the input was valid. */
+  private _lastValueValid = false;
 
   constructor(
       private _elementRef: ElementRef,
@@ -270,6 +285,8 @@ export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAcces
 
   _onInput(value: string) {
     let date = this._dateAdapter.parse(value, this._dateFormats.parse.dateInput);
+    this._lastValueValid = !date || this._dateAdapter.isValid(date);
+    date = this._getValidDateOrNull(date);
     this._cvaOnChange(date);
     this._valueChange.emit(date);
     this.dateInput.emit(new MdDatepickerInputEvent(this, this._elementRef.nativeElement));
@@ -278,4 +295,12 @@ export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAcces
   _onChange() {
     this.dateChange.emit(new MdDatepickerInputEvent(this, this._elementRef.nativeElement));
   }
+
+  /**
+   * @param obj The object to check.
+   * @returns The given object if it is both a date instance and valid, otherwise null.
+   */
+  private _getValidDateOrNull(obj: any): D | null {
+    return (this._dateAdapter.isDateInstance(obj) && this._dateAdapter.isValid(obj)) ? obj : null;
+  }
 }

src/lib/datepicker/datepicker.spec.ts

@@ -223,6 +223,15 @@ describe('MdDatepicker', () => {
         expect(ownedElement).not.toBeNull();
         expect((ownedElement as Element).tagName.toLowerCase()).toBe('md-calendar');
       });
+
+      it('should throw when given wrong data type', () => {
+        testComponent.date = '1/1/2017' as any;
+
+        expect(() => fixture.detectChanges())
+            .toThrowError(/Datepicker: value not recognized as a date object by DateAdapter\./);
+
+        testComponent.date = null;
+      });
     });
 
     describe('datepicker with too many inputs', () => {
@@ -902,7 +911,7 @@ describe('MdDatepicker', () => {
 class StandardDatepicker {
   touch = false;
   disabled = false;
-  date = new Date(2020, JAN, 1);
+  date: Date | null = new Date(2020, JAN, 1);
   @ViewChild('d') datepicker: MdDatepicker<Date>;
   @ViewChild(MdDatepickerInput) datepickerInput: MdDatepickerInput<Date>;
 }
@@ -1008,7 +1017,7 @@ class InputContainerDatepicker {
 })
 class DatepickerWithMinAndMaxValidation {
   @ViewChild('d') datepicker: MdDatepicker<Date>;
-  date: Date;
+  date: Date | null;
   minDate = new Date(2010, JAN, 1);
   maxDate = new Date(2020, JAN, 1);
 }

src/lib/datepicker/datepicker.ts

@@ -124,13 +124,13 @@ export class MdDatepickerContent<D> implements AfterContentInit {
 export class MdDatepicker<D> implements OnDestroy {
   /** The date to open the calendar to initially. */
   @Input()
-  get startAt(): D {
+  get startAt(): D | null {
     // If an explicit startAt is set we start there, otherwise we start at whatever the currently
     // selected value is.
     return this._startAt || (this._datepickerInput ? this._datepickerInput.value : null);
   }
-  set startAt(date: D) { this._startAt = date; }
-  private _startAt: D;
+  set startAt(date: D | null) { this._startAt = date; }
+  private _startAt: D | null;
 
   /** The view that the calendar should start in. */
   @Input() startView: 'month' | 'year' = 'month';
@@ -164,15 +164,17 @@ export class MdDatepicker<D> implements OnDestroy {
   id = `md-datepicker-${datepickerUid++}`;
 
   /** The currently selected date. */
-  _selected: D | null = null;
+  get _selected(): D | null { return this._validSelected; }
+  set _selected(value: D | null) { this._validSelected = value; }
+  private _validSelected: D | null = null;
 
   /** The minimum selectable date. */
-  get _minDate(): D {
+  get _minDate(): D | null {
     return this._datepickerInput && this._datepickerInput.min;
   }
 
   /** The maximum selectable date. */
-  get _maxDate(): D {
+  get _maxDate(): D | null {
     return this._datepickerInput && this._datepickerInput.max;
   }
 
@@ -240,7 +242,7 @@ export class MdDatepicker<D> implements OnDestroy {
     }
     this._datepickerInput = input;
     this._inputSubscription =
-        this._datepickerInput._valueChange.subscribe((value: D) => this._selected = value);
+        this._datepickerInput._valueChange.subscribe((value: D | null) => this._selected = value);
   }
 
   /** Open the calendar. */