[Major] Error behaviour when empty string in textarea

projects/dxc-ngx-cdk-site/src/app/components/examples/textarea/textarea-properties/textarea-properties.component.html

@@ -22,7 +22,8 @@
     <td>defaultValue: string</td>
     <td></td>
     <td>
-      Default value given to the textarea when is uncontrolled and also maintains the uncontrolled behaviour.
+      Default value given to the textarea when is uncontrolled and also
+      maintains the uncontrolled behaviour.
     </td>
   </tr>
   <tr>
@@ -59,8 +60,9 @@
     </td>
     <td>
       If true, the input will be optional, showing <code>(Optional)</code>
-      next to the label. Otherwise, the field will be considered required and an error 
-      will be passed as a parameter to the OnBlur and onChange functions when it has not been filled.
+      next to the label. Otherwise, the field will be considered required and an
+      error will be passed as a parameter to the OnBlur and onChange functions
+      when it has not been filled.
     </td>
   </tr>
   <tr>
@@ -94,9 +96,12 @@
     <td>error: string</td>
     <td></td>
     <td>
-      If it is defined, the component will change its appearance, showing the
-      error below the textarea component. If it is not defined, the error
-      messages will be created and managed internally.
+      If it is a defined value and also a truthy string, the component will
+      change its appearance, showing the error below the textarea. If the
+      defined value is an empty string, it will reserve a space below the
+      component for a future error, but it would not change its look. In case of
+      being undefined or null, both the appearance and the space for the error
+      message would not be modified.
     </td>
   </tr>
   <tr>
@@ -198,4 +203,4 @@
       ...
     </td>
   </tr>
-</dxc-table>
+</dxc-table>

projects/dxc-ngx-cdk-site/src/app/pages/theme-builder/previews/textarea-preview/textarea-preview.component.html

@@ -7,20 +7,24 @@
         [pattern]="pattern"
         (onBlur)="onBlur($event)"
         tabIndexValue="3"
+        margin="xsmall"
       >
       </dxc-textarea>
       <dxc-textarea
         label="default value"
         [pattern]="pattern"
         defaultValue="Default"
+        margin="xsmall"
       >
       </dxc-textarea>
     </tbuilder-component-mode>
     <tbuilder-component-mode text="Invalid">
-      <dxc-textarea label="Test" error="error"> </dxc-textarea>
+      <dxc-textarea label="Test" error="error" margin="xsmall"> </dxc-textarea>
+      <dxc-textarea label="Test" error="" margin="xsmall"> </dxc-textarea>
     </tbuilder-component-mode>
     <tbuilder-component-mode text="Disabled">
-      <dxc-textarea label="Test" value="test" disabled="true"> </dxc-textarea>
+      <dxc-textarea label="Test" value="test" disabled="true" margin="xsmall">
+      </dxc-textarea>
     </tbuilder-component-mode>
   </background-provider>
 

projects/dxc-ngx-cdk/src/lib/dxc-textarea/dxc-textarea.component.html

@@ -19,4 +19,8 @@
   (focus)="handleOnFocus()"
   [attr.autocomplete]="autocomplete"
 ></textarea>
-<span *ngIf="error && !disabled" class="textareaErrorMessage">{{ error }}</span>
+<span
+  *ngIf="(error || error === '') && !disabled"
+  class="textareaErrorMessage"
+  >{{ error }}</span
+>

projects/dxc-ngx-cdk/src/lib/dxc-textarea/dxc-textarea.component.spec.ts

@@ -131,9 +131,15 @@ describe("DxcTextareaComponent", () => {
     expect(textarea).toHaveFocus();
     fireEvent.click(textarea);
     fireEvent.input(textarea, { target: { value: "pattern4&" } });
-    expect(onChange).toHaveBeenCalledWith({ error: null, value: "pattern4&" });
+    expect(onChange).toHaveBeenCalledWith({
+      error: undefined,
+      value: "pattern4&",
+    });
     fireEvent.blur(textarea);
-    expect(onBlur).toHaveBeenCalledWith({ error: null, value: "pattern4&" });
+    expect(onBlur).toHaveBeenCalledWith({
+      error: undefined,
+      value: "pattern4&",
+    });
     expect(screen.getByDisplayValue("pattern4&"));
   });
   test("Strict mode - Length constraint", async () => {
@@ -176,7 +182,10 @@ describe("DxcTextareaComponent", () => {
     fireEvent.input(textarea, { target: { value: "test 2" } });
     fireEvent.blur(textarea);
     await waitFor(() => {
-      expect(onBlur).toHaveBeenCalledWith({ error: null, value: "test 2" });
+      expect(onBlur).toHaveBeenCalledWith({
+        error: undefined,
+        value: "test 2",
+      });
     });
   });
   test("Strict mode - Pattern and length constraints", async () => {
@@ -227,7 +236,7 @@ describe("DxcTextareaComponent", () => {
     fireEvent.click(textarea);
     fireEvent.input(textarea, { target: { value: "test 4" } });
     fireEvent.blur(textarea);
-    expect(onBlur).toHaveBeenCalledWith({ error: null, value: "test 4" });
+    expect(onBlur).toHaveBeenCalledWith({ error: undefined, value: "test 4" });
   });
   test("Non Strict mode - Pattern constraint", async () => {
     const onChange = jest.fn((value) => {
@@ -351,7 +360,10 @@ describe("DxcTextareaComponent", () => {
     fireEvent.input(textarea, { target: { value: "Blur test" } });
     fireEvent.blur(textarea);
     expect(onBlur).toHaveBeenCalled();
-    expect(onBlur).toHaveBeenCalledWith({ value: "Blur test", error: null });
+    expect(onBlur).toHaveBeenCalledWith({
+      value: "Blur test",
+      error: undefined,
+    });
   });
   test("Controlled textarea", async () => {
     const onChange = jest.fn();
@@ -382,13 +394,13 @@ describe("DxcTextareaComponent", () => {
       expect(screen.getByDisplayValue("test"));
       expect(onChange).toHaveBeenCalledWith({
         value: "Controlled test",
-        error: null,
+        error: undefined,
       });
     });
     fireEvent.blur(textarea);
     await waitFor(() => {
       expect(onBlur).toHaveBeenCalled();
-      expect(onBlur).toHaveBeenCalledWith({ value: "test", error: null });
+      expect(onBlur).toHaveBeenCalledWith({ value: "test", error: undefined });
     });
   });
   test("Uncontrolled input", async () => {
@@ -415,7 +427,7 @@ describe("DxcTextareaComponent", () => {
     expect(onChange).toHaveBeenCalled();
     expect(onChange).toHaveBeenCalledWith({
       value: "Uncontrolled test",
-      error: null,
+      error: undefined,
     });
     expect(textarea.value).toBe("Uncontrolled test");
   });

projects/dxc-ngx-cdk/src/lib/dxc-textarea/dxc-textarea.component.ts

@@ -68,7 +68,7 @@ export class DxcTextareaComponent implements OnInit {
   }
   private _disabled = false;
   /**
-   * If true, the textarea will be optional, showing (Optional) next to the label. 
+   * If true, the textarea will be optional, showing (Optional) next to the label.
    * Otherwise, the field will be considered required and an error will be passed as a parameter to the OnBlur and onChange functions when it has not been filled.
    */
   @Input()
@@ -99,8 +99,12 @@ export class DxcTextareaComponent implements OnInit {
   @Input()
   verticalGrow: "auto" | "manual" | "none" = "auto";
   /**
-   * If it is defined, the component will change its appearance, showing the error below the textarea component. 
-   * If it is not defined, the error messages will be created and managed internally.
+   * If it is a defined value and also a truthy string, the component will
+   * change its appearance, showing the error below the textarea. If the defined
+   * value is an empty string, it will reserve a space below the component for a
+   * future error, but it would not change its look. In case of being undefined
+   * or null, both the appearance and the space for the error message would not
+   * be modified.
    */
   @Input()
   error = undefined;
@@ -110,34 +114,34 @@ export class DxcTextareaComponent implements OnInit {
   @Input()
   placeholder = "";
   /**
-   * Regular expression that defines the valid format allowed by the textarea. 
-   * This will be checked when the textarea loses the focus. 
-   * If the value entered does not match the pattern, the onBlur function will be called with the value 
-   * entered and the error informing that the value does not match the pattern as parameters. If the pattern is accomplished, 
+   * Regular expression that defines the valid format allowed by the textarea.
+   * This will be checked when the textarea loses the focus.
+   * If the value entered does not match the pattern, the onBlur function will be called with the value
+   * entered and the error informing that the value does not match the pattern as parameters. If the pattern is accomplished,
    * the error parameter will be null.
    */
   @Input()
   pattern = "";
   /**
-   * Specifies the minimun length allowed by the textarea. 
-   * This will be checked both when the input element loses the focus and while typing within it. 
-   * If the string entered does not comply the minimum length, the onBlur and onChange functions will be called 
-   * with the current value and an internal error informing that the value length does not comply the specified range. 
+   * Specifies the minimun length allowed by the textarea.
+   * This will be checked both when the input element loses the focus and while typing within it.
+   * If the string entered does not comply the minimum length, the onBlur and onChange functions will be called
+   * with the current value and an internal error informing that the value length does not comply the specified range.
    * If a valid length is reached, the error parameter of both events will be null.
    */
   @Input()
   minLength: number;
   /**
-   * Specifies the maximum length allowed by the textarea. 
-   * This will be checked both when the input element loses the focus and while typing within it. 
-   * If the string entered does not comply the maximum length, the onBlur and onChange functions will be called 
-   * with the current value and an internal error informing that the value length does not comply the specified range. 
+   * Specifies the maximum length allowed by the textarea.
+   * This will be checked both when the input element loses the focus and while typing within it.
+   * If the string entered does not comply the maximum length, the onBlur and onChange functions will be called
+   * with the current value and an internal error informing that the value length does not comply the specified range.
    * If a valid length is reached, the error parameter of both events will be null.
    */
   @Input()
   maxLength: number;
   /**
-   * Size of the margin to be applied to the component ('xxsmall' | 'xsmall' | 'small' | 'medium' | 'large' | 'xlarge' | 'xxlarge'). 
+   * Size of the margin to be applied to the component ('xxsmall' | 'xsmall' | 'small' | 'medium' | 'large' | 'xlarge' | 'xxlarge').
    * You can pass an object with 'top', 'bottom', 'left' and 'right' properties in order to specify different margin sizes.
    */
   @Input()
@@ -161,7 +165,7 @@ export class DxcTextareaComponent implements OnInit {
   private controlled: boolean;
   defaultInputs = new BehaviorSubject<TextareaProperties>({
     placeholder: "",
-    error: "",
+    error: undefined,
     optional: false,
     disabled: false,
     helperText: "",
@@ -175,13 +179,13 @@ export class DxcTextareaComponent implements OnInit {
     verticalGrow: "auto",
   });
   /**
-   * This event will emit when the user types within the textarea. An object including the new value and the error will be passed to this function. 
+   * This event will emit when the user types within the textarea. An object including the new value and the error will be passed to this function.
    * An example of this object is: { value: value, error: error }. If there is no error, error will be null.
    */
   @Output()
   onChange = new EventEmitter<EmittedValue>();
   /**
-   * This event will emit when the textarea loses the focus. An object including the textarea value and the error will be passed to this function. 
+   * This event will emit when the textarea loses the focus. An object including the textarea value and the error will be passed to this function.
    * An example of this object is: { value: value, error: error }. If there is no error, error will be null.
    */
   @Output()
@@ -275,7 +279,7 @@ export class DxcTextareaComponent implements OnInit {
       return `Min length ${this.minLength}, Max length ${this.maxLength}`;
     if (value && !this.patternMatch(this.pattern, value))
       return `Please use a valid pattern`;
-    return null;
+    return undefined;
   }
   private handleValidationError() {
     const validationError = this.validateValue(this.value);
@@ -315,4 +319,4 @@ export class DxcTextareaComponent implements OnInit {
       }
     }
   }
-}
+}