import {expect} from "chai"; import checkRests from "../private_metre_checkRests"; const opts = {dotsAllowed: true}; function _expectRestChk(ts: string, song: string) { return expect(checkRests(ts, song.length, song, opts)); } describe("checkRests (Grouping rests according to the metre)", function() { // These rules are from _Behind Bars_ by _Elaine Gould_. You should buy that book. it("groups rests to clarify the divisions of the bar, ensuring that " + "rests with the division of one or more beats may start only on a beat.", function() { _expectRestChk("4/4", ".r__r___") .to.equal("apply 8 ..r_...."); _expectRestChk("4/4", ".rr_r___") .to.equal("GOOD"); _expectRestChk("4/4", "r_.r_.r_") .to.equal("apply 8 ....r..."); _expectRestChk("4/4", "r_.rr.r_") .to.equal("GOOD"); _expectRestChk("3/4", ".r__..") .to.equal("apply 6 ..r_.."); _expectRestChk("3/4", ".rr_..") .to.equal("GOOD"); }); describe("divides rests to expose the middle of the bar", function() { it("in simple time", function() { _expectRestChk("4/8", "r__.") .to.equal("apply 4 ..r."); _expectRestChk("4/8", "r_r.") .to.equal("GOOD"); _expectRestChk("4/8", ".r_.") .to.equal("apply 4 ..r."); _expectRestChk("4/8", ".rr.") .to.equal("GOOD"); _expectRestChk("4/8", ".r__") .to.equal("apply 4 ..r_"); _expectRestChk("4/8", ".rr_") .to.equal("GOOD"); _expectRestChk("2/4", "r__.") .to.equal("apply 4 ..r."); _expectRestChk("2/4", "r_r.") .to.equal("GOOD"); _expectRestChk("2/4", ".r_.") .to.equal("apply 4 ..r."); _expectRestChk("2/4", ".rr.") .to.equal("GOOD"); _expectRestChk("2/4", ".r__") .to.equal("apply 4 ..r_"); _expectRestChk("2/4", ".rr_") .to.equal("GOOD"); _expectRestChk("4/4", "r__.") .to.equal("apply 4 ..r."); _expectRestChk("4/4", "r_r.") .to.equal("GOOD"); _expectRestChk("4/4", ".r_.") .to.equal("apply 4 ..r."); _expectRestChk("4/4", ".rr.") .to.equal("GOOD"); _expectRestChk("4/4", ".r__") .to.equal("apply 4 ..r_"); _expectRestChk("4/4", ".rr_") .to.equal("GOOD"); _expectRestChk("2/2", "r__.") .to.equal("apply 4 ..r."); _expectRestChk("2/2", "r_r.") .to.equal("GOOD"); _expectRestChk("4/4", ".r_.") .to.equal("apply 4 ..r."); _expectRestChk("4/4", ".rr.") .to.equal("GOOD"); _expectRestChk("2/2", ".r__") .to.equal("apply 4 ..r_"); _expectRestChk("2/2", ".rr_") .to.equal("GOOD"); _expectRestChk("2/2", "..r_____") .to.equal("apply 8 ....r___"); _expectRestChk("2/2", "..r_r___") .to.equal("GOOD"); }); it("in compound time", function() { _expectRestChk("6/16", "r__rr.") .to.equal("apply 6 ...r_."); _expectRestChk("6/16", "r__r_.") .to.equal("GOOD"); _expectRestChk("6/16", "..rr..") .to.equal("GOOD"); _expectRestChk("6/16", ".rrr__") .to.equal("GOOD"); _expectRestChk("6/8", "r__r_.") .to.equal("GOOD"); _expectRestChk("6/4", "r__r_.") .to.equal("GOOD"); _expectRestChk("12/8", "r_____r__r_.") .to.equal("GOOD"); _expectRestChk("6/16", ".r_rr.") .to.equal("apply 6 ...r_."); _expectRestChk("6/16", ".r_r_.") .to.equal("apply 6 ..r..."); _expectRestChk("6/16", ".rrr_.") .to.equal("GOOD"); }); }); it("shows all beats in metres of three beats " + "(a two-beat rest belongs to a metre of two or four beats)", function() { _expectRestChk("3/4", "r_.") .to.equal("apply 3 .r."); _expectRestChk("3/4", "rr.") .to.equal("GOOD"); _expectRestChk("3/4", ".r_") .to.equal("apply 3 ..r"); _expectRestChk("3/4", ".rr") .to.equal("GOOD"); _expectRestChk("3/8", "r_.") .to.equal("apply 3 .r."); _expectRestChk("3/8", "rr.") .to.equal("GOOD"); _expectRestChk("3/8", ".r_") .to.equal("apply 3 ..r"); _expectRestChk("3/8", ".rr") .to.equal("GOOD"); _expectRestChk("9/8", "r_____...") .to.equal("apply 9 ...r__..."); _expectRestChk("9/8", "r__r__...") .to.equal("GOOD"); }); describe("Handling of dotted rests", function() { it("allows for older editions, which do not use dotted rests", function() { expect(checkRests("2/4", 8, "r__.r_r.", {dotsAllowed: false})) .to.equal("apply 8 ..r....."); expect(checkRests("2/4", 8, "r_r.r_r.", {dotsAllowed: false})) .to.equal("GOOD"); expect(checkRests("2/4", 8, "r_r.r__.", {dotsAllowed: false})) .to.equal("apply 8 ......r."); expect(checkRests("2/4", 8, "r_r.r_r.", {dotsAllowed: false})) .to.equal("GOOD"); expect(checkRests("9/8", 9, "r_rr_rr_.", {dotsAllowed: false})) .to.equal("GOOD"); expect(checkRests("9/8", 9, ".rrr_rr_r", {dotsAllowed: false})) .to.equal("GOOD"); expect(checkRests("2/4", 16, "r______.........", {dotsAllowed: false})) .to.equal("apply 16 ....r__........."); expect(checkRests("2/4", 16, "r_____..........", {dotsAllowed: false})) .to.equal("apply 16 ....r_.........."); }); describe("allows for rests within a beat to be combined", function() { it("(basic)", function() { _expectRestChk("2/4", "r__.r__.") .to.equal("GOOD"); _expectRestChk("9/8", "r_rr_rr_.") .to.equal("apply 9 r__......"); _expectRestChk("9/8", "r__r_rr_.") .to.equal("apply 9 ...r__..."); _expectRestChk("9/8", "r__r__r_.") .to.equal("GOOD"); _expectRestChk("9/8", ".rrr_rr_r") .to.equal("apply 9 ...r__..."); _expectRestChk("9/8", ".rrr__r_r") .to.equal("apply 9 ......r__"); _expectRestChk("9/8", ".rrr__r__") .to.equal("GOOD"); _expectRestChk("2/4", "r______.........") .to.equal("GOOD"); }); describe("in simple time", function() { it("Rests at the beginning and end of beats: the recommended practice is to use " + "dotted rests at the begining but not at the end of a beat. This visually " + "identifies on which part of the beat the rests fall:", function() { _expectRestChk("2/4", "r__..rr_") .to.equal("GOOD"); _expectRestChk("2/2", "r__..rr_") .to.equal("GOOD"); _expectRestChk("2/4", "r__..r_r") .to.equal("apply 8 ......r."); _expectRestChk("2/4", "r__..rrr") .to.equal("apply 8 ......r_"); _expectRestChk("2/4", "r__..rr_") .to.equal("GOOD"); _expectRestChk("2/4", "rrr.....") .to.equal("apply 8 r__....."); _expectRestChk("2/4", "r__.....") .to.equal("GOOD"); }); it("It is acceptable to use dotted rests at both the beginning and the end of a beat, " + "although the visual sifference between the types of rest is lost", function() { _expectRestChk("2/4", "r__..r__") .to.equal("GOOD"); _expectRestChk("2/2", "r__..r__") .to.equal("GOOD"); }); it("The longest permitted dotted rest is one value smaller than the beat. In " + "crotchet metres, the longest dotted rest is a dotted quaver", function() { _expectRestChk("4/4", "r______.") .to.equal("apply 8 ....r__."); _expectRestChk("4/4", "r___r__.") .to.equal("apply 8 ......r."); _expectRestChk("4/4", "r___r_r.") .to.equal("GOOD"); _expectRestChk("4/4", "r__.r___r_______") .to.equal("GOOD"); }); it("In minim metres, the longest dotted rest is a dotted crotchet:", function() { _expectRestChk("2/2", "r_____r.") .to.equal("apply 8 ....r_.."); _expectRestChk("2/2", "r__.r__.") .to.equal("GOOD"); _expectRestChk("2/2", ".rr_r___") .to.equal("GOOD"); }); it("The dotted-minim rest is normally never used in simple time. The only " + "exception is to show units of three crotchets in time signatures such as 5/4 and " + "also 7/4.", function() { // TODO }); it("Double-dotted rests: these may replace two or more rests within a beat", function() { _expectRestChk("2/4", "r______..r______") .to.equal("GOOD"); }); it("When it is useful to differentiate rests before and after a beat, use the double " + "dotting only at the beginning of a beat", function() { _expectRestChk("2/4", "r______..rr_r___") .to.equal("GOOD"); }); it("When it is preferable to show more clearly how the beat is divided, divide " + "the rest into half-beats:", function() { _expectRestChk("2/4", "r___r__..rr_r___") .to.equal("GOOD"); _expectRestChk("4/4", "rr_.....") .to.equal("apply 8 ..r....."); _expectRestChk("4/4", "rrr.....") .to.equal("apply 8 r_......"); _expectRestChk("4/4", "r_r.....") .to.equal("GOOD"); }); it("Rests in the middle of a beat: these should expose the middle of a beat:", function() { _expectRestChk("2/4", ".r_____.r_______") .to.equal("apply 16 ....r__........."); _expectRestChk("2/4", ".r__r__.r_______") .to.equal("GOOD"); _expectRestChk("2/4", ".rr_r__.r_______") .to.equal("GOOD"); }); it("but may be combined when rhythms are straightforward (TODO)", function() { _expectRestChk("2/4", ".r_..r_.") .to.equal("apply 8 ..r....."); _expectRestChk("2/4", ".rr..r_.") .to.equal("apply 8 ......r."); _expectRestChk("2/4", ".rr..rr.") .to.equal("GOOD"); }); }); describe("in compound time", function() { it("The dotted rest as a whole beat differentiates compound- from simple-time " + "metres.\n" + "Whole beats may be combined as long as the rests do not obscure the important " + "divisions of the bar. Otherwise, no rest should be written across a beat: ", function() { _expectRestChk("12/8", "r_________________......") .to.equal("apply 24 ............r_____......"); _expectRestChk("12/8", "r___________r_____......") .to.equal("GOOD"); _expectRestChk("12/8", "......r_____r___________") .to.equal("GOOD"); }); it("Rests within a beat: rests at the beginning of a beat may be combined:", function() { _expectRestChk("6/8", "rr.r_.") .to.equal("apply 6 r_...."); _expectRestChk("6/8", "r_.r_.") .to.equal("GOOD"); }); it("When there are alternative ways of combining rests, it is better to indicate " + "the second rather than the third division of the beat, since this clarifies the " + "divisions more quickly", function() { _expectRestChk("6/8", "r___r.r_____") .to.equal("GOOD"); // ^^ XXX: wrong _expectRestChk("6/8", "r_r__.r_____") .to.equal("apply 12 ....r......."); // ^^ XXX: wrong _expectRestChk("6/8", "r_r_r.r_____") .to.equal("apply 12 r___........"); // ^^ XXX: wrong _expectRestChk("6/8", "r___r.r_____") .to.equal("GOOD"); // ^^ XXX: wrong }); it("Rests that follow a beat should expose all three divisions", function() { _expectRestChk("6/8", "..r_r_..r_r_") .to.equal("GOOD"); }); it("If it is important for a performer to sense all three divisions of and " + "accompanying part, rests at the beginning of the beat should show these", function() { // TODO }); it("Otherwise it is better to combine the rests, as this clarifies the position of beats, " + "especially in long bars.", function() { _expectRestChk("9/8", ".rrrr.rr.") .to.equal("apply 9 ...r_...."); }); it("In the middle of a beat, rests must expose at least two of the three divisions. " + "Indicate all three divisions if this is important to the musical sense.", function() { // TODO }); }); }); }); it("does not allow impossible rest durations", function() { _expectRestChk("4/4", "r____...........") .to.equal("apply 16 ....r..........."); _expectRestChk("4/4", "r____...........................") .to.equal("apply 32 ....r..........................."); }); });