1 files changed, 367 insertions, 0 deletions
diff --git a/src/data/things/validators.js b/src/data/things/validators.js
new file mode 100644
index 0000000..cc603d4
--- /dev/null
+++ b/src/data/things/validators.js
@@ -0,0 +1,367 @@
+import {withAggregate} from '../../util/sugar.js';
+
+import {color, ENABLE_COLOR} from '../../util/cli.js';
+
+import {inspect as nodeInspect} from 'util';
+
+function inspect(value) {
+  return nodeInspect(value, {colors: ENABLE_COLOR});
+}
+
+// Basic types (primitives)
+
+function a(noun) {
+  return /[aeiou]/.test(noun[0]) ? `an ${noun}` : `a ${noun}`;
+}
+
+function isType(value, type) {
+  if (typeof value !== type)
+    throw new TypeError(`Expected ${a(type)}, got ${typeof value}`);
+
+  return true;
+}
+
+export function isBoolean(value) {
+  return isType(value, 'boolean');
+}
+
+export function isNumber(value) {
+  return isType(value, 'number');
+}
+
+export function isPositive(number) {
+  isNumber(number);
+
+  if (number <= 0) throw new TypeError(`Expected positive number`);
+
+  return true;
+}
+
+export function isNegative(number) {
+  isNumber(number);
+
+  if (number >= 0) throw new TypeError(`Expected negative number`);
+
+  return true;
+}
+
+export function isPositiveOrZero(number) {
+  isNumber(number);
+
+  if (number < 0) throw new TypeError(`Expected positive number or zero`);
+
+  return true;
+}
+
+export function isNegativeOrZero(number) {
+  isNumber(number);
+
+  if (number > 0) throw new TypeError(`Expected negative number or zero`);
+
+  return true;
+}
+
+export function isInteger(number) {
+  isNumber(number);
+
+  if (number % 1 !== 0) throw new TypeError(`Expected integer`);
+
+  return true;
+}
+
+export function isCountingNumber(number) {
+  isInteger(number);
+  isPositive(number);
+
+  return true;
+}
+
+export function isWholeNumber(number) {
+  isInteger(number);
+  isPositiveOrZero(number);
+
+  return true;
+}
+
+export function isString(value) {
+  return isType(value, 'string');
+}
+
+export function isStringNonEmpty(value) {
+  isString(value);
+
+  if (value.trim().length === 0)
+    throw new TypeError(`Expected non-empty string`);
+
+  return true;
+}
+
+// Complex types (non-primitives)
+
+export function isInstance(value, constructor) {
+  isObject(value);
+
+  if (!(value instanceof constructor))
+    throw new TypeError(`Expected ${constructor.name}, got ${value.constructor.name}`);
+
+  return true;
+}
+
+export function isDate(value) {
+  return isInstance(value, Date);
+}
+
+export function isObject(value) {
+  isType(value, 'object');
+
+  // Note: Please remember that null is always a valid value for properties
+  // held by a CacheableObject. This assertion is exclusively for use in other
+  // contexts.
+  if (value === null) throw new TypeError(`Expected an object, got null`);
+
+  return true;
+}
+
+export function isArray(value) {
+  if (typeof value !== 'object' || value === null || !Array.isArray(value))
+    throw new TypeError(`Expected an array, got ${value}`);
+
+  return true;
+}
+
+function validateArrayItemsHelper(itemValidator) {
+  return (item, index) => {
+    try {
+      const value = itemValidator(item);
+
+      if (value !== true) {
+        throw new Error(`Expected validator to return true`);
+      }
+    } catch (error) {
+      error.message = `(index: ${color.green(index)}, item: ${inspect(item)}) ${error.message}`;
+      throw error;
+    }
+  };
+}
+
+export function validateArrayItems(itemValidator) {
+  const fn = validateArrayItemsHelper(itemValidator);
+
+  return (array) => {
+    isArray(array);
+
+    withAggregate({message: 'Errors validating array items'}, ({wrap}) => {
+      array.forEach(wrap(fn));
+    });
+
+    return true;
+  };
+}
+
+export function validateInstanceOf(constructor) {
+  return (object) => isInstance(object, constructor);
+}
+
+// Wiki data (primitives & non-primitives)
+
+export function isColor(color) {
+  isStringNonEmpty(color);
+
+  if (color.startsWith('#')) {
+    if (![4, 5, 7, 9].includes(color.length))
+      throw new TypeError(`Expected #rgb, #rgba, #rrggbb, or #rrggbbaa, got length ${color.length}`);
+
+    if (/[^0-9a-fA-F]/.test(color.slice(1)))
+      throw new TypeError(`Expected hexadecimal digits`);
+
+    return true;
+  }
+
+  throw new TypeError(`Unknown color format`);
+}
+
+export function isCommentary(commentary) {
+  return isString(commentary);
+}
+
+const isArtistRef = validateReference('artist');
+
+export function validateProperties(spec) {
+  const specEntries = Object.entries(spec);
+  const specKeys = Object.keys(spec);
+
+  return (object) => {
+    isObject(object);
+
+    if (Array.isArray(object))
+      throw new TypeError(`Expected an object, got array`);
+
+    withAggregate({message: `Errors validating object properties`}, ({call}) => {
+      for (const [specKey, specValidator] of specEntries) {
+        call(() => {
+          const value = object[specKey];
+          try {
+            specValidator(value);
+          } catch (error) {
+            error.message = `(key: ${color.green(specKey)}, value: ${inspect(value)}) ${error.message}`;
+            throw error;
+          }
+        });
+      }
+
+      const unknownKeys = Object.keys(object).filter((key) => !specKeys.includes(key));
+      if (unknownKeys.length > 0) {
+        call(() => {
+          throw new Error(`Unknown keys present (${unknownKeys.length}): [${unknownKeys.join(', ')}]`);
+        });
+      }
+    });
+
+    return true;
+  };
+}
+
+export const isContribution = validateProperties({
+  who: isArtistRef,
+  what: (value) =>
+    value === undefined ||
+    value === null ||
+    isStringNonEmpty(value),
+});
+
+export const isContributionList = validateArrayItems(isContribution);
+
+export const isAdditionalFile = validateProperties({
+  title: isString,
+  description: (value) =>
+    value === undefined ||
+    value === null ||
+    isString(value),
+  files: validateArrayItems(isString),
+});
+
+export const isAdditionalFileList = validateArrayItems(isAdditionalFile);
+
+export function isDimensions(dimensions) {
+  isArray(dimensions);
+
+  if (dimensions.length !== 2) throw new TypeError(`Expected 2 item array`);
+
+  isPositive(dimensions[0]);
+  isInteger(dimensions[0]);
+  isPositive(dimensions[1]);
+  isInteger(dimensions[1]);
+
+  return true;
+}
+
+export function isDirectory(directory) {
+  isStringNonEmpty(directory);
+
+  if (directory.match(/[^a-zA-Z0-9_-]/))
+    throw new TypeError(`Expected only letters, numbers, dash, and underscore, got "${directory}"`);
+
+  return true;
+}
+
+export function isDuration(duration) {
+  isNumber(duration);
+  isPositiveOrZero(duration);
+
+  return true;
+}
+
+export function isFileExtension(string) {
+  isStringNonEmpty(string);
+
+  if (string[0] === '.')
+    throw new TypeError(`Expected no dot (.) at the start of file extension`);
+
+  if (string.match(/[^a-zA-Z0-9_]/))
+    throw new TypeError(`Expected only alphanumeric and underscore`);
+
+  return true;
+}
+
+export function isLanguageCode(string) {
+  // TODO: This is a stub function because really we don't need a detailed
+  // is-language-code parser right now.
+
+  isString(string);
+
+  return true;
+}
+
+export function isName(name) {
+  return isString(name);
+}
+
+export function isURL(string) {
+  isStringNonEmpty(string);
+
+  new URL(string);
+
+  return true;
+}
+
+export function validateReference(type = 'track') {
+  return (ref) => {
+    isStringNonEmpty(ref);
+
+    const match = ref
+      .trim()
+      .match(/^(?:(?<typePart>\S+):(?=\S))?(?<directoryPart>.+)(?<!:)$/);
+
+    if (!match) throw new TypeError(`Malformed reference`);
+
+    const {groups: {typePart, directoryPart}} = match;
+
+    if (typePart) {
+      if (typePart !== type)
+        throw new TypeError(`Expected ref to begin with "${type}:", got "${typePart}:"`);
+
+      isDirectory(directoryPart);
+    }
+
+    isName(ref);
+
+    return true;
+  };
+}
+
+export function validateReferenceList(type = '') {
+  return validateArrayItems(validateReference(type));
+}
+
+// Compositional utilities
+
+export function oneOf(...checks) {
+  return (value) => {
+    const errorMeta = [];
+
+    for (let i = 0, check; (check = checks[i]); i++) {
+      try {
+        const result = check(value);
+
+        if (result !== true) {
+          throw new Error(`Check returned false`);
+        }
+
+        return true;
+      } catch (error) {
+        errorMeta.push([check, i, error]);
+      }
+    }
+
+    // Don't process error messages until every check has failed.
+    const errors = [];
+    for (const [check, i, error] of errorMeta) {
+      error.message = check.name
+        ? `(#${i} "${check.name}") ${error.message}`
+        : `(#${i}) ${error.message}`;
+      error.check = check;
+      errors.push(error);
+    }
+    throw new AggregateError(errors, `Expected one of ${checks.length} possible checks, but none were true`);
+  };
+}