Extend generic property descriptor handling

* Integrate scripts/generate*.mjs scripts into scripts/prepare.mjs.
* Add serializeDimension function in lib/parsers.js, and rename various parseX → serializeX.
* Add handlers for various AST_TYPES in the generic property descriptors.
* Fix bugs in properties/backgroundPosition.js and properties/backgroundRepeat.js handlers.

Author: asamuzaK

lib/parsers.js

@@ -374,7 +374,7 @@ function parsePropertyValue(prop, val, opt = {}) {
 
 /**
  * Parses a numeric value (number, dimension, percentage).
- * Helper function for parseNumber, parseLength, etc.
+ * Helper function for serializeNumber, serializeLength, etc.
  *
  * @param {Array<object>} val - The AST value.
  * @param {object} [opt={}] - The options for parsing.
@@ -408,13 +408,13 @@ function parseNumericValue(val, opt, validateType) {
 }
 
 /**
- * Parses a <number> value.
+ * Serializes a <number> value.
  *
  * @param {Array<object>} val - The AST value.
  * @param {object} [opt={}] - The options for parsing.
  * @returns {string|undefined} The parsed number.
  */
-function parseNumber(val, opt = {}) {
+function serializeNumber(val, opt = {}) {
   const res = parseNumericValue(val, opt, (type) => type === AST_TYPES.NUMBER);
   if (!res) {
     return;
@@ -423,13 +423,13 @@ function parseNumber(val, opt = {}) {
 }
 
 /**
- * Parses a <length> value.
+ * Serializes an <angle> value.
  *
  * @param {Array<object>} val - The AST value.
  * @param {object} [opt={}] - The options for parsing.
- * @returns {string|undefined} The parsed length.
+ * @returns {string|undefined} The serialized angle.
  */
-function parseLength(val, opt = {}) {
+function serializeAngle(val, opt = {}) {
   const res = parseNumericValue(
     val,
     opt,
@@ -439,67 +439,85 @@ function parseLength(val, opt = {}) {
     return;
   }
   const { num, unit } = res;
-  if (num === 0 && !unit) {
-    return `${num}px`;
-  } else if (unit) {
+  if (unit) {
+    if (!/^(?:deg|g?rad|turn)$/i.test(unit)) {
+      return;
+    }
     return `${num}${unit}`;
+  } else if (num === 0) {
+    return `${num}deg`;
   }
 }
 
 /**
- * Parses a <percentage> value.
+ * Serializes a <length> value.
  *
  * @param {Array<object>} val - The AST value.
  * @param {object} [opt={}] - The options for parsing.
- * @returns {string|undefined} The parsed percentage.
+ * @returns {string|undefined} The serialized length.
  */
-function parsePercentage(val, opt = {}) {
+function serializeLength(val, opt = {}) {
   const res = parseNumericValue(
     val,
     opt,
-    (type, value) => type === AST_TYPES.PERCENTAGE || (type === AST_TYPES.NUMBER && value === "0")
+    (type, value) => type === AST_TYPES.DIMENSION || (type === AST_TYPES.NUMBER && value === "0")
   );
   if (!res) {
     return;
   }
-  const { num } = res;
-  return `${num}%`;
+  const { num, unit } = res;
+  if (num === 0 && !unit) {
+    return `${num}px`;
+  } else if (unit) {
+    return `${num}${unit}`;
+  }
 }
 
 /**
- * Parses an <angle> value.
+ * Serializes a <dimension> value, e.g. <frequency>, <time> and <resolution>.
  *
  * @param {Array<object>} val - The AST value.
  * @param {object} [opt={}] - The options for parsing.
- * @returns {string|undefined} The parsed angle.
+ * @returns {string|undefined} The serialized dimension.
  */
-function parseAngle(val, opt = {}) {
-  const res = parseNumericValue(
-    val,
-    opt,
-    (type, value) => type === AST_TYPES.DIMENSION || (type === AST_TYPES.NUMBER && value === "0")
-  );
+function serializeDimension(val, opt = {}) {
+  const res = parseNumericValue(val, opt, (type) => type === AST_TYPES.DIMENSION);
   if (!res) {
     return;
   }
   const { num, unit } = res;
   if (unit) {
-    if (!/^(?:deg|g?rad|turn)$/i.test(unit)) {
-      return;
-    }
     return `${num}${unit}`;
-  } else if (num === 0) {
-    return `${num}deg`;
   }
 }
 
 /**
- * Parses a <url> value.
+ * Serializes a <percentage> value.
+ *
+ * @param {Array<object>} val - The AST value.
+ * @param {object} [opt={}] - The options for parsing.
+ * @returns {string|undefined} The serialized percentage.
+ */
+function serializePercentage(val, opt = {}) {
+  const res = parseNumericValue(
+    val,
+    opt,
+    (type, value) => type === AST_TYPES.PERCENTAGE || (type === AST_TYPES.NUMBER && value === "0")
+  );
+  if (!res) {
+    return;
+  }
+  const { num } = res;
+  return `${num}%`;
+}
+
+/**
+ * Serializes a <url> value.
  *
  * @param {Array<object>} val - The AST value.
- * @returns {string|undefined} The parsed url.
+ * @returns {string|undefined} The serialized url.
  */
-function parseUrl(val) {
+function serializeURL(val) {
   const [item] = val;
   const { type, value } = item ?? {};
   if (type !== AST_TYPES.URL) {
@@ -510,12 +528,12 @@ function parseUrl(val) {
 }
 
 /**
- * Parses a <string> value.
+ * Serializes a <string> value.
  *
  * @param {Array<object>} val - The AST value.
- * @returns {string|undefined} The parsed string.
+ * @returns {string|undefined} The serialized string.
  */
-function parseString(val) {
+function serializeString(val) {
   const [item] = val;
   const { type, value } = item ?? {};
   if (type !== AST_TYPES.STRING) {
@@ -526,12 +544,12 @@ function parseString(val) {
 }
 
 /**
- * Parses a <color> value.
+ * Serializes a <color> value.
  *
  * @param {Array<object>} val - The AST value.
- * @returns {string|undefined} The parsed color.
+ * @returns {string|undefined} The serialized color.
  */
-function parseColor(val) {
+function serializeColor(val) {
   const [item] = val;
   const { name, type, value } = item ?? {};
   switch (type) {
@@ -570,12 +588,12 @@ function parseColor(val) {
 }
 
 /**
- * Parses a <gradient> value.
+ * Serializes a <gradient> value.
  *
  * @param {Array<object>} val - The AST value.
- * @returns {string|undefined} The parsed gradient.
+ * @returns {string|undefined} The serialized gradient.
  */
-function parseGradient(val) {
+function serializeGradient(val) {
   const [item] = val;
   const { name, type, value } = item ?? {};
   if (type !== AST_TYPES.FUNCTION) {
@@ -656,9 +674,11 @@ function resolveNumericValue(value, opt = {}) {
     }
     case AST_TYPES.DIMENSION: {
       if (type === "angle") {
-        return parseAngle(value, opt);
+        return serializeAngle(value, opt);
+      } else if (type === "length") {
+        return serializeLength(value, opt);
       }
-      return parseLength(value, opt);
+      return serializeDimension(value, opt);
     }
     case AST_TYPES.GLOBAL_KEYWORD: {
       if (length > 1) {
@@ -672,21 +692,21 @@ function resolveNumericValue(value, opt = {}) {
     case AST_TYPES.NUMBER: {
       switch (type) {
         case "angle": {
-          return parseAngle(value, opt);
+          return serializeAngle(value, opt);
         }
         case "length": {
-          return parseLength(value, opt);
+          return serializeLength(value, opt);
         }
         case "percentage": {
-          return parsePercentage(value, opt);
+          return serializePercentage(value, opt);
         }
         default: {
-          return parseNumber(value, opt);
+          return serializeNumber(value, opt);
         }
       }
     }
     case AST_TYPES.PERCENTAGE: {
-      return parsePercentage(value, opt);
+      return serializePercentage(value, opt);
     }
     default:
   }
@@ -710,7 +730,7 @@ function resolveColorValue(value, opt = {}) {
       return name;
     }
     default: {
-      return parseColor(value, opt);
+      return serializeColor(value, opt);
     }
   }
 }
@@ -736,10 +756,10 @@ function resolveImageValue(value, opt = {}) {
       return name;
     }
     case AST_TYPES.URL: {
-      return parseUrl(value, opt);
+      return serializeURL(value, opt);
     }
     default: {
-      return parseGradient(value, opt);
+      return serializeGradient(value, opt);
     }
   }
 }
@@ -767,7 +787,7 @@ function resolveBorderShorthandValue(value, subProps, parsedValues) {
       if (parsedValues.has(widthProp)) {
         return;
       }
-      const parsedValue = parseLength(value, { min: 0 });
+      const parsedValue = serializeLength(value, { min: 0 });
       if (!parsedValue) {
         return;
       }
@@ -778,7 +798,7 @@ function resolveBorderShorthandValue(value, subProps, parsedValues) {
       if (parsedValues.has(colorProp)) {
         return;
       }
-      const parsedValue = parseColor(value);
+      const parsedValue = serializeColor(value);
       if (!parsedValue) {
         return;
       }
@@ -816,16 +836,8 @@ module.exports = {
   hasVarFunc,
   isGlobalKeyword,
   isValidPropertyValue,
-  parseAngle,
   parseCSS,
-  parseColor,
-  parseGradient,
-  parseLength,
-  parseNumber,
-  parsePercentage,
   parsePropertyValue,
-  parseString,
-  parseUrl,
   prepareValue,
   resolveBorderShorthandValue,
   resolveCalc,
@@ -834,5 +846,14 @@ module.exports = {
   resolveImageValue,
   resolveKeywordValue,
   resolveNumericValue,
+  serializeAngle,
+  serializeColor,
+  serializeDimension,
+  serializeGradient,
+  serializeLength,
+  serializeNumber,
+  serializePercentage,
+  serializeString,
+  serializeURL,
   splitValue
 };

lib/properties/backgroundPosition.js

@@ -56,15 +56,21 @@ function parse(v) {
       let parsedValue = "";
       switch (value.length) {
         case 1: {
-          const val1 =
-            part1.type === AST_TYPES.IDENTIFIER ? part1.name : parsers.resolveNumericValue([part1], { type: "length" });
-          if (val1) {
-            if (val1 === "center") {
-              parsedValue = `${val1} ${val1}`;
-            } else if (val1 === "top" || val1 === "bottom") {
-              parsedValue = `center ${val1}`;
-            } else {
-              parsedValue = `${val1} center`;
+          if (part1.type === AST_TYPES.GLOBAL_KEYWORD) {
+            parsedValue = part1.name;
+          } else {
+            const val1 =
+              part1.type === AST_TYPES.IDENTIFIER
+                ? part1.name
+                : parsers.resolveNumericValue([part1], { type: "length" });
+            if (val1) {
+              if (val1 === "center") {
+                parsedValue = `${val1} ${val1}`;
+              } else if (val1 === "top" || val1 === "bottom") {
+                parsedValue = `center ${val1}`;
+              } else {
+                parsedValue = `${val1} center`;
+              }
             }
           }
           break;

lib/properties/backgroundRepeat.js

@@ -51,9 +51,8 @@ function parse(v) {
       switch (value.length) {
         case 1: {
           const [part1] = value;
-          const val1 = part1.type === AST_TYPES.IDENTIFIER && part1.name;
-          if (val1) {
-            parsedValue = val1;
+          if (part1.type === AST_TYPES.GLOBAL_KEYWORD || part1.type === AST_TYPES.IDENTIFIER) {
+            parsedValue = part1.name;
           }
           break;
         }