scale-generator: Require N+1 notes from N intervals

The problem has been explained in
exercism/problem-specifications#1640:

All previous cases only required N notes from N intervals, but that
meant the last interval was completely ignored.
That causes confusion (what is the last interval there for?).

To fix this, all tests with the `interval` property are updated.

The `tonic` and `intervals` inputs have not changed. The `expected` has
changed only in that there is one more note added, indicated by the last
interval, which was previously ignored.

exercism/problem-specifications#1888

exercises/practice/scale-generator/.meta/example.rs

@@ -346,9 +346,10 @@ impl Scale {
         let mut out = Vec::with_capacity(self.intervals.len());
 
         let mut note = self.tonic;
+        out.push(note.canonicalize(self.lean).to_string());
         for &interval in self.intervals.iter() {
-            out.push(note.canonicalize(self.lean).to_string());
             note += interval;
+            out.push(note.canonicalize(self.lean).to_string());
         }
 
         out

exercises/practice/scale-generator/tests/scale-generator.rs

@@ -35,7 +35,7 @@ fn test_chromatic_scale_with_sharps() {
     process_chromatic_case(
         "C",
         &[
-            "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B",
+            "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B", "C",
         ],
     );
 }
@@ -47,7 +47,7 @@ fn test_chromatic_scale_with_flats() {
     process_chromatic_case(
         "F",
         &[
-            "F", "Gb", "G", "Ab", "A", "Bb", "B", "C", "Db", "D", "Eb", "E",
+            "F", "Gb", "G", "Ab", "A", "Bb", "B", "C", "Db", "D", "Eb", "E", "F",
         ],
     );
 }
@@ -62,70 +62,90 @@ fn test_chromatic_scale_with_flats() {
 ///
 /// The simplest major scale, with no sharps or flats.
 fn test_simple_major_scale() {
-    process_interval_case("C", "MMmMMMm", &["C", "D", "E", "F", "G", "A", "B"]);
+    process_interval_case("C", "MMmMMMm", &["C", "D", "E", "F", "G", "A", "B", "C"]);
 }
 
 #[test]
 #[ignore]
 /// Major scale with sharps
 fn test_major_scale_with_sharps() {
-    process_interval_case("G", "MMmMMMm", &["G", "A", "B", "C", "D", "E", "F#"]);
+    process_interval_case("G", "MMmMMMm", &["G", "A", "B", "C", "D", "E", "F#", "G"]);
 }
 
 #[test]
 #[ignore]
 /// Major scale with flats
 fn test_major_scale_with_flats() {
-    process_interval_case("F", "MMmMMMm", &["F", "G", "A", "Bb", "C", "D", "E"]);
+    process_interval_case("F", "MMmMMMm", &["F", "G", "A", "Bb", "C", "D", "E", "F"]);
 }
 
 #[test]
 #[ignore]
 /// Minor scale with sharps
 fn test_minor_scale_with_sharps() {
-    process_interval_case("f#", "MmMMmMM", &["F#", "G#", "A", "B", "C#", "D", "E"]);
+    process_interval_case(
+        "f#",
+        "MmMMmMM",
+        &["F#", "G#", "A", "B", "C#", "D", "E", "F#"],
+    );
 }
 
 #[test]
 #[ignore]
 /// Minor scale with flats
 fn test_minor_scale_with_flats() {
-    process_interval_case("bb", "MmMMmMM", &["Bb", "C", "Db", "Eb", "F", "Gb", "Ab"]);
+    process_interval_case(
+        "bb",
+        "MmMMmMM",
+        &["Bb", "C", "Db", "Eb", "F", "Gb", "Ab", "Bb"],
+    );
 }
 
 #[test]
 #[ignore]
 /// Dorian mode
 fn test_dorian_mode() {
-    process_interval_case("d", "MmMMMmM", &["D", "E", "F", "G", "A", "B", "C"]);
+    process_interval_case("d", "MmMMMmM", &["D", "E", "F", "G", "A", "B", "C", "D"]);
 }
 
 #[test]
 #[ignore]
 /// Mixolydian mode
 fn test_mixolydian_mode() {
-    process_interval_case("Eb", "MMmMMmM", &["Eb", "F", "G", "Ab", "Bb", "C", "Db"]);
+    process_interval_case(
+        "Eb",
+        "MMmMMmM",
+        &["Eb", "F", "G", "Ab", "Bb", "C", "Db", "Eb"],
+    );
 }
 
 #[test]
 #[ignore]
 /// Lydian mode
 fn test_lydian_mode() {
-    process_interval_case("a", "MMMmMMm", &["A", "B", "C#", "D#", "E", "F#", "G#"]);
+    process_interval_case(
+        "a",
+        "MMMmMMm",
+        &["A", "B", "C#", "D#", "E", "F#", "G#", "A"],
+    );
 }
 
 #[test]
 #[ignore]
 /// Phrygian mode
 fn test_phrygian_mode() {
-    process_interval_case("e", "mMMMmMM", &["E", "F", "G", "A", "B", "C", "D"]);
+    process_interval_case("e", "mMMMmMM", &["E", "F", "G", "A", "B", "C", "D", "E"]);
 }
 
 #[test]
 #[ignore]
 /// Locrian mode
 fn test_locrian_mode() {
-    process_interval_case("g", "mMMmMMM", &["G", "Ab", "Bb", "C", "Db", "Eb", "F"]);
+    process_interval_case(
+        "g",
+        "mMMmMMM",
+        &["G", "Ab", "Bb", "C", "Db", "Eb", "F", "G"],
+    );
 }
 
 #[test]
@@ -134,7 +154,7 @@ fn test_locrian_mode() {
 ///
 /// Note that this case introduces the augmented second interval (A)
 fn test_harmonic_minor() {
-    process_interval_case("d", "MmMMmAm", &["D", "E", "F", "G", "A", "Bb", "Db"]);
+    process_interval_case("d", "MmMMmAm", &["D", "E", "F", "G", "A", "Bb", "Db", "D"]);
 }
 
 #[test]
@@ -144,27 +164,31 @@ fn test_octatonic() {
     process_interval_case(
         "C",
         "MmMmMmMm",
-        &["C", "D", "D#", "F", "F#", "G#", "A", "B"],
+        &["C", "D", "D#", "F", "F#", "G#", "A", "B", "C"],
     );
 }
 
 #[test]
 #[ignore]
 /// Hexatonic
 fn test_hexatonic() {
-    process_interval_case("Db", "MMMMMM", &["Db", "Eb", "F", "G", "A", "B"]);
+    process_interval_case("Db", "MMMMMM", &["Db", "Eb", "F", "G", "A", "B", "Db"]);
 }
 
 #[test]
 #[ignore]
 /// Pentatonic
 fn test_pentatonic() {
-    process_interval_case("A", "MMAMA", &["A", "B", "C#", "E", "F#"]);
+    process_interval_case("A", "MMAMA", &["A", "B", "C#", "E", "F#", "A"]);
 }
 
 #[test]
 #[ignore]
 /// Enigmatic
 fn test_enigmatic() {
-    process_interval_case("G", "mAMMMmm", &["G", "G#", "B", "C#", "D#", "F", "F#"]);
+    process_interval_case(
+        "G",
+        "mAMMMmm",
+        &["G", "G#", "B", "C#", "D#", "F", "F#", "G"],
+    );
 }