export class StepMock implements Xrm.ProcessFlow.Step {
  public required: boolean;
  public name: string;
  public attribute: string;

  constructor(name: string, attribute: string, required: boolean) {
      this.name = name;
      this.attribute = attribute;
      this.required = required;
  }

  public getAttribute(): string {
      return this.attribute;
  }

  public getName(): string {
      return this.name;
  }

  public isRequired(): boolean {
      return this.required;
  }

  public getProgress(): number {
    throw new Error("getProgress not implemented");
  }

  public setProgress(stepProgress: number, message: string): string {
    throw new Error("setProgress not implemented");
  }
}

export class StepMock implements Xrm.ProcessFlow.Step {
  public required: boolean;
  public name: string;
  public attribute: string;

  constructor(name: string, attribute: string, required: boolean) {
      this.name = name;
      this.attribute = attribute;
      this.required = required;
  }

  public getAttribute(): string {
      return this.attribute;
  }

  public getName(): string {
      return this.name;
  }

  public isRequired(): boolean {
      return this.required;
  }
}

--- 
+++ 
@@ -20,4 +20,12 @@
   public isRequired(): boolean {
       return this.required;
   }
+
+  public getProgress(): number {
+    throw new Error("getProgress not implemented");
+  }
+
+  public setProgress(stepProgress: number, message: string): string {
+    throw new Error("setProgress not implemented");
+  }
 }
Add missing functions in the steps method of formContext.data.process
