Added test cases for list.go and github.go

Author: irapandey

hack/tools/release/notes/list_test.go

@@ -65,3 +65,143 @@ func Test_buildSetOfPRNumbers(t *testing.T) {
 		})
 	}
 }
+
+func Test_githubFromToPRLister_listPRs(t *testing.T) {
+	type fields struct {
+		client  *githubClient
+		fromRef *ref
+		toRef   *ref
+		branch  string
+	}
+	type args struct {
+		previousReleaseRef ref
+	}
+	tests := []struct {
+		name    string
+		fields  *githubFromToPRLister
+		args    ref
+		wantErr bool
+	}{
+		{
+			name: "Successful PR Listing",
+			fields: &githubFromToPRLister{
+				client:  &githubClient{
+					repo:    "kubernetes-sigs/kind",
+				},
+				fromRef: ref{
+					reType: "tags",
+					value: "v0.26.0",
+				},
+				toRef: ref{
+					reType: "tags",
+					value: "v0.27.0",
+				},
+				branch:  "main",
+			},
+			args: ref{
+				reType: "tags",
+				value: "v0.26.0",
+			},
+			wantErr: false,
+		},
+		{
+			name: "Setting previousReleaseRef.value blank - should use toRef and fromRef from fields",
+			fields: &githubFromToPRLister{
+				client:  &githubClient{
+					repo:    "kubernetes-sigs/kind",
+				},
+				fromRef: ref{
+					reType: "tags",
+					value: "v0.26.0",
+				},
+				toRef: ref{
+					reType: "tags",
+					value: "v0.27.0",
+				},
+				branch:  "main",
+			},
+			args: ref{
+				reType: "tags",
+				value: "",
+			},
+			wantErr: false,
+		},
+		{
+			name: "Create PR List when fromRef is not set",
+			fields: &githubFromToPRLister{
+				client:  &githubClient{
+					repo:    "kubernetes-sigs/kind",
+				},
+				toRef: ref{
+					reType: "tags",
+					value: "v0.27.0",
+				},
+				branch:  "main",
+			},
+			args: ref{
+				reType: "tags",
+				value: "v0.26.0",
+			},
+			wantErr: false,
+		},
+		{
+			name: "Fail when previousReleaseRef.value is set to invalid",
+			fields: &githubFromToPRLister{
+				client:  &githubClient{
+					repo:    "kubernetes-sigs/kind",
+				},
+				fromRef: ref{
+					reType: "tags",
+					value: "v0.26.0",
+				},
+				toRef: ref{
+					reType: "tags",
+					value: "v0.27.0",
+				},
+				branch:  "main",
+			},
+			args: ref{
+				reType: "tags",
+				value: "invalid",
+			},
+			wantErr: true,
+		},
+		{
+			name: "Fail when toRef and previousReleaseRef set blank",
+			fields: &githubFromToPRLister{
+				client:  &githubClient{
+					repo:    "kubernetes-sigs/kind",
+				},
+				fromRef: ref{
+					reType: "tags",
+					value: "v0.26.0",
+				},
+				toRef: ref{
+					reType: "tags",
+					value: "",
+				},
+				branch:  "main",
+			},
+			args: ref{
+				reType: "tags",
+				value: "",
+			},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			l := &githubFromToPRLister{
+				client:  tt.fields.client,
+				fromRef: tt.fields.fromRef,
+				toRef:   tt.fields.toRef,
+				branch:  tt.fields.branch,
+			}
+			_, err := l.listPRs(tt.args)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("githubFromToPRLister.listPRs() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+		})
+	}
+}