1 files changed, 208 insertions, 0 deletions
diff --git a/src/thing/validators.js b/src/thing/validators.js
new file mode 100644
index 00000000..05736914
--- /dev/null
+++ b/src/thing/validators.js
@@ -0,0 +1,208 @@
+import { withAggregate } from '../util/sugar.js';
+
+// 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 isInteger(number) {
+    isNumber(number);
+
+    if (number % 1 !== 0)
+        throw new TypeError(`Expected integer`);
+
+    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)
+
+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) {
+    isObject(value);
+
+    if (!Array.isArray(value))
+        throw new TypeError(`Expected an array, got ${value}`);
+
+    return true;
+}
+
+export function validateArrayItems(itemValidator) {
+    return array => {
+        isArray(array);
+
+        withAggregate({message: 'Errors validating array items'}, ({ wrap }) => {
+            array.forEach(wrap(itemValidator));
+        });
+
+        return true;
+    };
+}
+
+// Wiki data (primitives & non-primitives)
+
+export function isColor(color) {
+    isStringNonEmpty(color);
+
+    if (color.startsWith('#')) {
+        if (![1 + 3, 1 + 4, 1 + 6, 1 + 8].includes(color.length))
+            throw new TypeError(`Expected #rgb, #rgba, #rrggbb, or #rrggbbaa, got length ${color.length}`);
+
+        if (/[^0-9a-fA-F]/.test(color.slice(1)))
+            throw new TypeError(`Expected hexadecimal digits`);
+
+        return true;
+    }
+
+    throw new TypeError(`Unknown color format`);
+}
+
+export function isCommentary(commentary) {
+    return isString(commentary);
+}
+
+const isArtistRef = validateReference('artist');
+
+export function isContribution(contrib) {
+    // TODO: Use better object validation for this (supporting aggregates etc)
+
+    isObject(contrib);
+
+    isArtistRef(contrib.who);
+
+    if (contrib.what !== null) {
+        isStringNonEmpty(contrib.what);
+    }
+
+    return true;
+}
+
+export const isContributionList = validateArrayItems(isContribution);
+
+export function isDimensions(dimensions) {
+    isArray(dimensions);
+
+    if (dimensions.length !== 2)
+        throw new TypeError(`Expected 2 item array`);
+
+    isPositive(dimensions[0]);
+    isInteger(dimensions[0]);
+    isPositive(dimensions[1]);
+    isInteger(dimensions[1]);
+
+    return true;
+}
+
+export function isDirectory(directory) {
+    isStringNonEmpty(directory);
+
+    if (directory.match(/[^a-zA-Z0-9\-]/))
+        throw new TypeError(`Expected only letters, numbers, and dash, got "${directory}"`);
+
+    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 hasTwoParts = ref.includes(':');
+        const [ typePart, directoryPart ] = ref.split(':');
+
+        if (hasTwoParts && typePart !== type)
+            throw new TypeError(`Expected ref to begin with "${type}:", got "${typePart}:" (ref: ${ref})`);
+
+        if (hasTwoParts)
+            isDirectory(directoryPart);
+
+        isName(ref);
+
+        return true;
+    };
+}
+
+export function validateReferenceList(type = '') {
+    return validateArrayItems(validateReference(type));
+}