testing/debug_utils library

Testing/Debug: pretty-print, dump iterable, assert equals with tolerance, range, repeat, timed. Roadmap #366-375.

Functions

assertEqualsWithTolerance(double a, double b, double tolerance) → void

Throws an AssertionError when a and b differ by more than tolerance.

dumpIterable(Iterable it, {int maxItems = 10}) → String

Renders it as a string, truncating to the first maxItems elements and appending the total count when the iterable is longer.

prettyPrint(Object? obj, {int indent = 0}) → String

Recursively renders obj as an indented, human-readable string for debugging. Maps and lists are expanded over multiple lines; null becomes 'null' and any other value falls back to its toString(). indent sets the starting nesting depth (two spaces per level).

rangeDouble(double start, double end, double step) → List<double>

Returns doubles from start (inclusive) toward end (exclusive) in increments of step. A negative step counts down; the result is empty when the range cannot advance toward end.

rangeInt(int start, int end, {int step = 1}) → List<int>

Returns integers from start (inclusive) toward end (exclusive) in increments of step. A negative step counts down; the result is empty when the range cannot advance toward end.

repeatValue<T>(T value, int n) → List<T>

Returns a list containing value repeated n times.

retryUntil(bool predicate(), {int maxAttempts = 10}) → bool

Calls predicate up to maxAttempts times, returning true as soon as it succeeds, or false if every attempt fails.

timed(void fn()) → Duration

Runs fn synchronously and returns the wall-clock Duration it took.