t.assert asserts properties

deno.json

@@ -0,0 +1,7 @@
+{
+  "imports": {
+    "isomorphic.js": "./node_modules/isomorphic.js/node.mjs",
+    "lib0/crypto": "./crypto.js",
+    "lib0/webcrypto": "./webcrypto.deno.js"
+  }
+}

encoding.test.js

@@ -489,6 +489,9 @@ const encodingPairs = [
 export const testRepeatRandomWrites = tc => {
   t.describe(`Writing ${loops} random values`, `defLen=${defLen}`)
   const gen = tc.prng
+  /**
+   * @type {any}
+   */
   const ops = []
   const encoder = encoding.createEncoder()
   for (let i = 0; i < 10000; i++) {

list.test.js

@@ -12,9 +12,9 @@ class QueueItem extends list.ListNode {
 }
 
 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
  */
-export const testEnqueueDequeue = tc => {
+export const testEnqueueDequeue = _tc => {
   const N = 30
   /**
    * @type {list.List<QueueItem>}
@@ -45,9 +45,9 @@ export const testEnqueueDequeue = tc => {
 }
 
 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
  */
-export const testSelectivePop = tc => {
+export const testSelectivePop = _tc => {
   /**
    * @type {list.List<QueueItem>}
    */

testing.js

@@ -511,12 +511,14 @@ const _compare = (a, b, path, message, customCompare) => {
 export const compare = (a, b, message = null, customCompare = compareValues) => _compare(a, b, 'obj', message, customCompare)
 
 /**
- * @param {boolean} condition
+ * @template T
+ * @param {T} property
  * @param {string?} [message]
+ * @return {asserts property is NonNullable<T>}
  * @throws {TestError}
  */
 /* c8 ignore next */
-export const assert = (condition, message = null) => condition || fail(`Assertion failed${message !== null ? `: ${message}` : ''}`)
+export const assert = (property, message = null) => { property || fail(`Assertion failed${message !== null ? `: ${message}` : ''}`) }
 
 /**
  * @param {function():Promise<any>} f

testing.test.js

@@ -10,6 +10,14 @@ export const nottestingNotTested = () => {
   t.assert(false, 'This test should not be executed because the name doesnt start with "test"')
 }
 
+export const testAssertTyping = () => {
+  const q = Math.random()
+  const x = q === 0.3 ? { a: 4 } : null
+  // t.assert(x.a === 4) - this will give a type error because the type is uncertain
+  t.assert(x)
+  t.assert(x.a === 4) // this works because x is asserted
+}
+
 /**
  * @param {t.TestCase} _tc
  */

webcrypto.deno.js

@@ -0,0 +1,4 @@
+// eslint-disable-next-line
+export const subtle = /** @type {any} */ (crypto).subtle
+// eslint-disable-next-line
+export const getRandomValues = /** @type {any} */ (crypto).getRandomValues.bind(crypto)