diff --git a/data/reminder_covers_event.testdata.json b/data/reminder_covers_event.testdata.json
new file mode 100644
index 0000000..8fca1b6
--- /dev/null
+++ b/data/reminder_covers_event.testdata.json
@@ -0,0 +1,122 @@
+[
+	{
+		"input": {
+			"reminder": {
+				"frequency": "daily",
+				"offset": 0,
+				"from": 24,
+				"to": 48
+			},
+			"event": {
+				"begin": {
+					"timezone_shift": 0,
+					"date": {
+						"year": 2025,
+						"month": 6,
+						"day": 25
+					},
+					"time": {
+						"hour": 12,
+						"minute": 0,
+						"second": 0
+					}
+				}
+			},
+			"datetime": {
+				"timezone_shift": 0,
+				"date": {
+					"year": 2025,
+					"month": 6,
+					"day": 23
+				},
+				"time": {
+					"hour": 10,
+					"minute": 0,
+					"second": 0
+				}
+			},
+			"interval": 1
+		},
+		"output": false
+	},
+	{
+		"input": {
+			"reminder": {
+				"frequency": "daily",
+				"offset": 0,
+				"from": 24,
+				"to": 48
+			},
+			"event": {
+				"begin": {
+					"timezone_shift": 0,
+					"date": {
+						"year": 2025,
+						"month": 6,
+						"day": 25
+					},
+					"time": {
+						"hour": 12,
+						"minute": 0,
+						"second": 0
+					}
+				}
+			},
+			"datetime": {
+				"timezone_shift": 0,
+				"date": {
+					"year": 2025,
+					"month": 6,
+					"day": 24
+				},
+				"time": {
+					"hour": 10,
+					"minute": 0,
+					"second": 0
+				}
+			},
+			"interval": 1
+		},
+		"output": true
+	},
+	{
+		"input": {
+			"reminder": {
+				"frequency": "daily",
+				"offset": 0,
+				"from": 24,
+				"to": 48
+			},
+			"event": {
+				"begin": {
+					"timezone_shift": 0,
+					"date": {
+						"year": 2025,
+						"month": 6,
+						"day": 25
+					},
+					"time": {
+						"hour": 12,
+						"minute": 0,
+						"second": 0
+					}
+				}
+			},
+			"datetime": {
+				"timezone_shift": 0,
+				"date": {
+					"year": 2025,
+					"month": 6,
+					"day": 25
+				},
+				"time": {
+					"hour": 10,
+					"minute": 0,
+					"second": 0
+				}
+			},
+			"interval": 1
+		},
+		"output": false
+	}
+]
diff --git a/data/reminder_due.testdata.json b/data/reminder_due.testdata.json
new file mode 100644
index 0000000..1d7211c
--- /dev/null
+++ b/data/reminder_due.testdata.json
@@ -0,0 +1,77 @@
+[
+	{
+		"input": {
+			"reminder": {
+				"frequency": "daily",
+				"offset": 16,
+				"from": 24,
+				"to": 48
+			},
+			"datetime": {
+				"timezone_shift": 0,
+				"date": {
+					"year": 2025,
+					"month": 6,
+					"day": 27
+				},
+				"time": {
+					"hour": 15,
+					"minute": 30,
+					"second": 0
+				}
+			},
+			"interval": 1
+		},
+		"output": false
+	},
+	{
+		"input": {
+			"reminder": {
+				"frequency": "daily",
+				"offset": 16,
+				"from": 24,
+				"to": 48
+			},
+			"datetime": {
+				"timezone_shift": 0,
+				"date": {
+					"year": 2025,
+					"month": 6,
+					"day": 27
+				},
+				"time": {
+					"hour": 16,
+					"minute": 30,
+					"second": 0
+				}
+			},
+			"interval": 1
+		},
+		"output": true
+	},
+	{
+		"input": {
+			"reminder": {
+				"frequency": "daily",
+				"offset": 16,
+				"from": 24,
+				"to": 48
+			},
+			"datetime": {
+				"timezone_shift": 0,
+				"date": {
+					"year": 2025,
+					"month": 6,
+					"day": 27
+				},
+				"time": {
+					"hour": 17,
+					"minute": 30,
+					"second": 0
+				}
+			},
+			"interval": 1
+		},
+		"output": false
+	}
+]
diff --git a/ivaldi.json b/ivaldi.json
index b3a009a..c3c033f 100644
--- a/ivaldi.json
+++ b/ivaldi.json
@@ -12,6 +12,8 @@
 					"email",
 					"telegram",
 					"url",
+					"json",
+					"file",
 					"conf",
 					"log",
 					"args"
@@ -20,6 +22,7 @@
 		}
 	],
 	"sources": [
+		"helpers/test.ts",
 		"types.ts",
 		"sources/ical_feed.ts",
 		"sources/_functions.ts",
diff --git a/source/helpers/test.ts b/source/helpers/test.ts
new file mode 100644
index 0000000..5c87834
--- /dev/null
+++ b/source/helpers/test.ts
@@ -0,0 +1,124 @@
+/*
+This file is part of »munin«.
+
+Copyright 2025 'Fenris Wolf' <fenris@folksprak.org>
+
+»munin« is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+»munin« is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with »munin«. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+namespace _munin.helpers.test
+{
+	
+	/**
+	 * @todo outsource
+	 */
+	type type_testcase_raw<type_input, type_output> = {
+		active ?: boolean;
+		name ?: string;
+		input : type_input;
+		output : type_output;
+	};
+	
+	
+	/**
+	 * @todo outsource
+	 */
+	export type type_testcase<type_input, type_output> = {
+		name : string;
+		input : type_input;
+		output : type_output;
+	};
+	
+	
+	/**
+	 * @todo outsource
+	 */
+	export async function get_data<type_input, type_output>(
+		path : string,
+		{
+			"default_active": default_active = true,
+		} : {
+			default_active ?: boolean;
+		} = {
+		}
+	) : Promise<Array<type_testcase<type_input, type_output>>>
+	{
+		const content : string = await lib_plankton.file.read(path);
+		const testcases_raw : Array<type_testcase_raw<type_input, type_output>> = (
+			lib_plankton.json.decode(content) as Array<type_testcase_raw<type_input, type_output>>
+		);
+		const testcases : Array<type_testcase<type_input, type_output>> = (
+			testcases_raw
+			.filter(
+				testcase_raw => (testcase_raw.active ?? default_active),
+			)
+			.map(
+				(testcase_raw, index) => ({
+					"name": (
+						testcase_raw.name
+						??
+						lib_plankton.string.coin(
+							"{{path}} | #{{index}}",
+							{
+								"path": path,
+								"index": (index + 1).toFixed(0),
+							}
+						)
+					),
+					"input": testcase_raw.input,
+					"output": testcase_raw.output,
+				})
+			)
+		);
+		return testcases;
+	}
+	
+	
+	/**
+	 * @todo outsource
+	 */
+	export function start(
+		name : string
+	) : void
+	{
+		lib_plankton.log._info(
+			"test.run",
+			{
+				"details": {
+					"name": name,
+				}
+			}
+		);
+	}
+	
+	
+	/**
+	 * @todo outsource
+	 */
+	export function fail(
+		name : string
+	) : void
+	{
+		lib_plankton.log._error(
+			"test.failed",
+			{
+				"details": {
+					"name": name,
+				}
+			}
+		);
+	}
+	
+}
diff --git a/source/logic.ts b/source/logic.ts
index a9efba2..9a76d62 100644
--- a/source/logic.ts
+++ b/source/logic.ts
@@ -21,6 +21,23 @@ along with »munin«. If not, see <http://www.gnu.org/licenses/>.
 namespace _munin.logic
 {
 	
+	/**
+	 */
+	export function frequency_decode(
+		frequency_encoded : string
+	) : _munin.enum_frequency
+	{
+		switch (frequency_encoded)
+		{
+			case "hourly": return _munin.enum_frequency.hourly;
+			case "daily": return _munin.enum_frequency.daily;
+			case "weekly": return _munin.enum_frequency.weekly;
+			case "monthly": return _munin.enum_frequency.monthly;
+			default: {throw new Error("unhandled");}
+		}
+	}
+	
+		
 	/**
 	 */
 	function frequency_anchor(
@@ -99,7 +116,7 @@ namespace _munin.logic
 	
 	/**
 	 */
-	export function reminder_event_in_window(
+	export function reminder_covers_event(
 		reminder : type_reminder,
 		event : _munin.type_event,
 		{
@@ -131,7 +148,7 @@ namespace _munin.logic
 			window_to
 		);
 		lib_plankton.log._info(
-			"munin.logic.reminder_event_in_window",
+			"munin.logic.reminder_covers_event",
 			{
 				"details": {
 					"reminder": reminder,
@@ -183,7 +200,7 @@ namespace _munin.logic
 				else
 				{
 					const events_matching : Array<_munin.type_event> = events.filter(
-						event => reminder_event_in_window(
+						event => reminder_covers_event(
 							reminder,
 							event,
 							{
diff --git a/source/test.ts b/source/test.ts
index 91bed40..b570f3f 100644
--- a/source/test.ts
+++ b/source/test.ts
@@ -20,192 +20,47 @@ along with »munin«. If not, see <http://www.gnu.org/licenses/>.
 
 namespace _munin.test
 {
-	
+
 	/**
 	 */
-	type type_datetime = {
-		year : int;
-		month : int;
-		day : int;
-		hour : int;
-		minute : int;
-		second : int;
-	};
-	
-	
-	/**
-	 */
-	function datetime_to_pit(
-		datetime : type_datetime
-	) : lib_plankton.pit.type_pit
+	async function reminder_due(
+	) : Promise<void>
 	{
-		return lib_plankton.pit.from_datetime(
-			{
-				"date": {
-					"year": datetime.year,
-					"month": datetime.month,
-					"day": datetime.day,
-				},
-				"time": {
-					"hour": datetime.hour,
-					"minute": datetime.minute,
-					"second": datetime.second,
-				},
-				"timezone_shift": 0,
-			}
-		);
-	}
-	
-	
-	/**
-	 */
-	function start(
-		name : string
-	) : void
-	{
-		lib_plankton.log._info(
-			"test.run",
-			{
-				"details": {
-					"name": name,
-				}
-			}
-		);
-	}
-	
-	
-	/**
-	 */
-	function fail(
-		name : string
-	) : void
-	{
-		lib_plankton.log._error(
-			"test.failed",
-			{
-				"details": {
-					"name": name,
-				}
-			}
-		);
-	}
-	
-	
-	/**
-	 */
-	function frequency_decode(
-		frequency_encoded : string
-	) : _munin.enum_frequency
-	{
-		switch (frequency_encoded)
-		{
-			case "hourly": return _munin.enum_frequency.hourly;
-			case "daily": return _munin.enum_frequency.daily;
-			case "weekly": return _munin.enum_frequency.weekly;
-			case "monthly": return _munin.enum_frequency.monthly;
-			default: {throw new Error("unhandled");}
-		}
-	}
-	
-	
-	/**
-	 */
-	export function reminder_due(
-	) : void
-	{
-		type type_testcase = {
-			name : string;
-			input : {
-				reminder : {
-					frequency : string;
-					offset : int;
-					from : int;
-					to : int;
-				};
-				datetime : type_datetime;
-				interval : int;
+		type type_input = {
+			reminder : {
+				frequency : string;
+				offset : int;
+				from : int;
+				to : int;
 			};
-			output : boolean;
+			datetime : lib_plankton.pit.type_datetime;
+			interval : int;
 		};
-		const testcases : Array<type_testcase> = [
+		type type_output = boolean;
+		const testcases : Array<
+			_munin.helpers.test.type_testcase<
+				type_input,
+				type_output
+			>
+		> = await _munin.helpers.test.get_data<type_input, type_output>(
+			"data/reminder_due.testdata.json",
 			{
-				"name": "reminder_due.test1",
-				"input": {
-					"reminder": {
-						"frequency": "daily",
-						"offset": 16,
-						"from": 24,
-						"to": 48
-					},
-					"datetime": {
-						"year": 2025,
-						"month": 6,
-						"day": 27,
-						"hour": 15,
-						"minute": 30,
-						"second": 0
-					},
-					"interval": 1
-				},
-				"output": false
-			},
-			{
-				"name": "reminder_due.test2",
-				"input": {
-					"reminder": {
-						"frequency": "daily",
-						"offset": 16,
-						"from": 24,
-						"to": 48
-					},
-					"datetime": {
-						"year": 2025,
-						"month": 6,
-						"day": 27,
-						"hour": 16,
-						"minute": 30,
-						"second": 0,
-					},
-					"interval": 1
-				},
-				"output": true
-			},
-			{
-				"name": "reminder_due.test3",
-				"input": {
-					"reminder": {
-						"frequency": "daily",
-						"offset": 16,
-						"from": 24,
-						"to": 48
-					},
-					"datetime": {
-						"year": 2025,
-						"month": 6,
-						"day": 27,
-						"hour": 17,
-						"minute": 30,
-						"second": 0
-					},
-					"interval": 1
-				},
-				"output": false
-			},
-		];
+			}
+		);
 		for (const testcase of testcases)
 		{
-			start(testcase.name);
+			_munin.helpers.test.start(testcase.name);
 			
 			// execution
 			const result : boolean = _munin.logic.reminder_due(
 				{
-					"frequency": frequency_decode(testcase.input.reminder.frequency),
+					"frequency": _munin.logic.frequency_decode(testcase.input.reminder.frequency),
 					"offset": testcase.input.reminder.offset,
 					"from": testcase.input.reminder.from,
 					"to": testcase.input.reminder.to,
 				},
 				{
-					"pit": datetime_to_pit(testcase.input.datetime),
+					"pit": lib_plankton.pit.from_datetime(testcase.input.datetime),
 					"interval": testcase.input.interval,
 				}
 			);
@@ -213,7 +68,7 @@ namespace _munin.test
 			// assertions
 			if (result !== testcase.output)
 			{
-				fail(testcase.name);
+				_munin.helpers.test.fail(testcase.name);
 			}
 		}
 	}
@@ -221,163 +76,75 @@ namespace _munin.test
 	
 	/**
 	 */
-	export function reminder_event_in_window(
-	) : void
+	async function reminder_covers_event(
+	) : Promise<void>
 	{
-		type type_testcase = {
-			name : string;
-			input : {
-				reminder : {
-					frequency : string;
-					offset : int;
-					from : int;
-					to : int;
-				};
-				event : {
-					begin : type_datetime;
-				};
-				datetime : type_datetime;
-				interval : int;
+		type type_input = {
+			reminder : {
+				frequency : string;
+				offset : int;
+				from : int;
+				to : int;
 			};
-			output : boolean;
+			event : {
+				begin : lib_plankton.pit.type_datetime;
+			};
+			datetime : lib_plankton.pit.type_datetime;
+			interval : int;
 		};
-		const testcases : Array<type_testcase> = [
+		type type_output = boolean;
+		const testcases : Array<
+			_munin.helpers.test.type_testcase<
+				type_input,
+				type_output
+			>
+		> = await _munin.helpers.test.get_data<type_input, type_output>(
+			"data/reminder_covers_event.testdata.json",
 			{
-				"name": "reminder_event_in_window.test1",
-				"input": {
-					"reminder": {
-						"frequency": "daily",
-						"offset": 0,
-						"from": 24,
-						"to": 48
-					},
-					"event": {
-						"begin": {
-							"year": 2025,
-							"month": 6,
-							"day": 25,
-							"hour": 12,
-							"minute": 0,
-							"second": 0
-						}
-					},
-					"datetime": {
-						"year": 2025,
-						"month": 6,
-						"day": 23,
-						"hour": 10,
-						"minute": 0,
-						"second": 0
-					},
-					"interval": 1
-				},
-				"output": false
-			},
-			{
-				"name": "reminder_event_in_window.test2",
-				"input": {
-					"reminder": {
-						"frequency": "daily",
-						"offset": 0,
-						"from": 24,
-						"to": 48
-					},
-					"event": {
-						"begin": {
-							"year": 2025,
-							"month": 6,
-							"day": 25,
-							"hour": 12,
-							"minute": 0,
-							"second": 0
-						}
-					},
-					"datetime": {
-						"year": 2025,
-						"month": 6,
-						"day": 24,
-						"hour": 10,
-						"minute": 0,
-						"second": 0
-					},
-					"interval": 1
-				},
-				"output": true
-			},
-			{
-				"name": "reminder_event_in_window.test3",
-				"input": {
-					"reminder": {
-						"frequency": "daily",
-						"offset": 0,
-						"from": 24,
-						"to": 48
-					},
-					"event": {
-						"begin": {
-							"year": 2025,
-							"month": 6,
-							"day": 25,
-							"hour": 12,
-							"minute": 0,
-							"second": 0
-						}
-					},
-					"datetime": {
-						"year": 2025,
-						"month": 6,
-						"day": 25,
-						"hour": 10,
-						"minute": 0,
-						"second": 0
-					},
-					"interval": 1
-				},
-				"output": false
-			},
-		];
+			}
+		);
 		
 		for (const testcase of testcases)
 		{
-			start(testcase.name);
+			_munin.helpers.test.start(testcase.name);
 			
 			// execution
-			const result : boolean = _munin.logic.reminder_event_in_window(
+			const result : boolean = _munin.logic.reminder_covers_event(
 				{
-					"frequency": frequency_decode(testcase.input.reminder.frequency),
+					"frequency": _munin.logic.frequency_decode(testcase.input.reminder.frequency),
 					"offset": testcase.input.reminder.offset,
 					"from": testcase.input.reminder.from,
 					"to": testcase.input.reminder.to,
 				},
 				{
 					"title": "test",
-					"begin": lib_plankton.pit.to_datetime(datetime_to_pit(testcase.input.event.begin)),
+					"begin": testcase.input.event.begin,
 					"end": null,
 					"description": null,
 					"location": null,
 					"tags": null,
 				},
 				{
-					"pit": datetime_to_pit(testcase.input.datetime),
+					"pit": lib_plankton.pit.from_datetime(testcase.input.datetime),
 				}
 			);
 			
 			// assertions
 			if (result !== testcase.output)
 			{
-				fail(testcase.name);
+				_munin.helpers.test.fail(testcase.name);
 			}
 		}
 	}
-	
+		
 	
 	/**
 	 */
-	export function all(
-	) : void
+	export async function all(
+	) : Promise<void>
 	{
-		reminder_due();
-		reminder_event_in_window();
+		await reminder_due();
+		await reminder_covers_event();
 	}
 	
 }
diff --git a/tools/build b/tools/build
index 155b24a..f85b346 100755
--- a/tools/build
+++ b/tools/build
@@ -1,4 +1,13 @@
-#!/usr/bin/env sh
+#!/usr/bin/env bash
 
+## core
 tools/ivaldi build
-cd build && npm install nodemailer ; cd -
+
+## data
+mkdir -p build/data
+cp -r -u -v data/* build/data/
+
+## node modules
+node_modules=""
+node_modules="${node_modules} nodemailer"
+cd build && npm install ${node_modules} ; cd -