Allow decimal numbers to be expressed as strings

Fixes #24

docs/source/schema.md

@@ -54,11 +54,14 @@ Contains information that applies to the whole set of charts
     - string, optional
     - Relative path to the jacket / album cover / album art to be shown in music select for example. usually a square image.
 - **BPM**
-    - number, required
+    - number or string, required
     - Song tempo in Beats per Minute.
+    - Striclty positive
+    - Strings allowed for easier decimal representation preservation
 - **offset**
-    - number, required
+    - number or string, required
     - In seconds, opposite of the time position of the first beat in the music file. For instance, if the first beat occurs at 0.15 seconds in the audio file, `offset̀` should be -0.15
+    - Strings allowed for easier decimal representation preservation
 - **preview**
     - object or string, optional
     - Contains either a {ref}`preview object <preview>` or a path to a bms-style preview file
@@ -76,11 +79,15 @@ Contains information that applies to the whole set of charts
 Describes the part of the music file that's meant to be played on loop when previewing this song at the music select screen
 
 - **start**
-    - number, required
+    - number or string, required
     - In seconds, start of the loop
+    - Positive
+    - Strings allowed for easier decimal representation preservation
 - **duration**
-    - number, required
+    - number or string, required
     - In seconds, duration of the loop
+    - Strictly positive
+    - Strings allowed for easier decimal representation preservation
 
 (data)=
 ## Data
@@ -165,7 +172,7 @@ A classic note.
 
           Ticks are fractions of the beat.
           The resolution defines how many ticks are in a beat for a given chart.
-          In other words if the resolution is 420, a tick lasts for 1/420th of a beat
+          In other words if the resolution is 420, a tick lasts for 1/420th oLike for the BPM, sf a beat
   
           For more info about measuring time in ticks, see [bmson's docs](https://bmson-spec.readthedocs.io/en/master/doc/index.html#terminologies) (their docs refers to ticks as *pulses*).
     - as an array :

docs/source/validation.md

@@ -103,19 +103,13 @@ Since this is mostly an implicit rule that's not strictly followed by official c
 
 ## Decimal values
 
-If possible, non-integer values like `BPM` or `offset` should be manipulated using a [Decimal Data Type](https://en.wikipedia.org/wiki/Decimal_data_type) to preserve their original decimal representation. I think no one likes to see the BPM they defined as a clean `195.3` in the editor be stored as a messy `195.3000030517578125` in the file.
+If possible, non-integer values like `BPM` or `offset` should be manipulated using a [Decimal Data Type](https://en.wikipedia.org/wiki/Decimal_data_type) to preserve their original decimal representation. I think no one likes to see the BPM they defined as a clean `195.3` in the editor be stored as a messy `195.3000030517578125` in the file. If doing this is too hard with your language / library of choice, keep in mind that `1.0.0` allows strings instead :
 
-Be careful that the serialized values in the resulting file must still be *number litterals*, not strings.
+- **Valid**
-
-- **Good**
   ```json
   { "BPM" : 195.3 }
   ```
-- **Bad**
+- **Valid since 1.0.0**
   ```json
   { "BPM": "195.3" }
-  ```
+  ```
-
-This is not that easy. Python's standard module `json`, for instance, allows *deserializing* (reading) numbers in a json file as `decimal.Decimal` instances, but has no easy way of *serializing* (writing) `decimal.Decimal` instances as a json number litteral that respects the original representation.
-
-A possible solution is to use the [simplejson](https://pypi.org/project/simplejson/) module as a near drop-in replacement for `json` and use the `use_decimal` options

schema.json

@@ -30,12 +30,11 @@
                 },
                 "BPM": {
                     "description": "Song tempo in Beats per Minute",
-                    "type": "number",
+                    "$ref": "#/$defs/strictlyPositiveDecimal"
-                    "exclusiveMinimum": 0
                 },
                 "offset": {
                     "description": "In seconds, opposite of the time position of the first beat in the music file",
-                    "type": "number"
+                    "$ref": "#/$defs/decimal"
                 },
                 "preview": {
                     "description": "Describes the part of the music file that's to be played on loop when previewing this song",
@@ -45,13 +44,11 @@
                             "properties": {
                                 "start": {
                                     "description": "In seconds, Time at which preview should start",
-                                    "type": "number",
+                                    "$ref": "#/$defs/positiveDecimal"
-                                    "minimum": 0
                                 },
                                 "duration": {
                                     "description": "In seconds, for how long should the preview be played past the starting point",
-                                    "type": "number",
+                                    "$ref": "#/$defs/strictlyPositiveDecimal"
-                                    "minimum": 0
                                 }
                             },
                             "required": ["start", "duration"]
@@ -180,6 +177,40 @@
                     }
                 }
             ]
+        },
+        "decimal": {
+            "description": "a decimal number as either a number literal or a string",
+            "oneOf": [{
+                "type": "number"
+            },
+            {
+                "type": "string",
+                "pattern": "^-?\\d+(\\.\\d+)?$"
+            }
+            ]
+        },
+        "positiveDecimal": {
+            "description": "a decimal number as either a number literal or a string",
+            "oneOf": [{
+                "type": "number"
+            },
+            {
+                "type": "string",
+                "pattern": "^\\d+(\\.\\d+)?$"
+            }
+            ]
+        },
+        "strictlyPositiveDecimal": {
+            "description": "a strictly positive decimal number as either a number literal or a string",
+            "oneOf": [{
+                "type": "number",
+                "exclusiveMinimum": 0
+            },
+            {
+                "type": "string",
+                "pattern": "^(0\\.\\d*[1-9]\\d*|\\d*[1-9]\\d*(\\.\\d+)?)$"
+            }
+            ]
         }
     }
 }

tests/data/02 - polymorphic preview/pass/good object.json

@@ -7,7 +7,7 @@
         "offset": 0,
         "preview": {
             "start": 0,
-            "duration": 0
+            "duration": 1
         }
     },
     "data": {}

tests/data/06 - decimals as string/fail/negative BPM number.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": -1,
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/fail/negative BPM string copy.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": "-1",
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/fail/preview object with decimal zero duration.json

@@ -0,0 +1,14 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": {
+            "start": "0",
+            "duration": "0.000"
+        }
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/fail/preview object with negative duration copy.json

@@ -0,0 +1,14 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": {
+            "start": "0",
+            "duration": "-10.000"
+        }
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/fail/preview object with zero duration copy.json

@@ -0,0 +1,14 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": {
+            "start": "0",
+            "duration": "0"
+        }
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/fail/zero BPM decimal string.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": "0.000",
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/fail/zero BPM number.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 0,
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/fail/zero BPM string.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": "0",
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/pass/decimal string BPM 1.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": "0.1",
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/pass/decimal string BPM 2.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": "123.456",
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/pass/decimal string offset 1.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 123.456,
+        "offset": "-0.24"
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/pass/decimal string offset 2.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 123.456,
+        "offset": "12.34"
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/pass/integer BPM.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 125,
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/pass/integer string BPM.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": "123",
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/pass/number BPM.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 123.456,
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/06 - decimals as string/pass/preview object.json

@@ -0,0 +1,14 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": {
+            "start": "8346.9346",
+            "duration": "35.936"
+        }
+    },
+    "data": {}
+}

tests/utils.py

@@ -7,7 +7,7 @@ from jschon.jsonschema import Scope
 from jschon import create_catalog, JSONSchema, JSON
 import pytest
 
-_catalog = create_catalog('2020-12')
+_catalog = create_catalog("2020-12")
 SCHEMA = JSONSchema.loadf("schema.json", catalog=_catalog)
 
 def prettify_path(json_path: str) -> str: