✨ Allow returning booleans and matchers from anonymous assertions

wwilsman · Jul 7, 2023 · b9cf306 · b9cf306
1 parent c7a51c3
commit b9cf306
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Showing 2 changed files with 65 additions and 8 deletions.
diff --git a/lib/assert.js b/lib/assert.js
@@ -22,8 +22,8 @@ export function assertion(get, matcher = get) {
       args = [value].concat(args);
     }
 
-    let { message, result } = matcher.apply(this, args);
-
+    let { message, result } =
+      matcher.apply(this, args);
     if (result !== expected)
       throw error(message);
   };
@@ -158,16 +158,23 @@ export default function InteractorAssert(i, expected = true) {
 
     // assertions are called with an assert context and can be negated on error
     return passert.call(i, defineProperties(function() {
+      let message;
+
       try {
-        f.apply(context(this, expected), arguments);
-        if (expected) return;
+        let res = f.apply(context(this, expected), arguments);
+        if (typeof res === 'object' && 'message' in res) message = res.message;
+        if (typeof res === 'object' && 'result' in res) res = !!res.result;
+        if (expected === !!(res ?? true)) return;
       } catch (err) {
         if (err.name === 'InteractorError') err.bind(this, expected);
         if (expected) throw err;
         return;
       }
 
-      throw error('expected assertion to fail but it passed');
+      throw error(message ?? [
+        'expected assertion to', expected ? 'pass' : 'fail',
+        'but it', expected ? 'failed' : 'passed'
+      ].join(' '));
     }, {
       name: { value: f.name },
       // used to determine invoking the interactor element

diff --git a/tests/assert.test.js b/tests/assert.test.js
@@ -8,6 +8,33 @@ describe('InteractorAssert', () => {
     assert.notEqual(I().assert, I().assert);
   });
 
+  it('handles boolean return values', async () => {
+    await assert.doesNotReject(
+      Test().assert(() => true)
+    );
+
+    await assert.rejects(
+      Test().assert(() => false),
+      e('InteractorError', 'expected assertion to pass but it failed')
+    );
+  });
+
+  it('handles matcher return values', async () => {
+    await assert.doesNotReject(
+      Test().assert(() => ({ result: true }))
+    );
+
+    await assert.rejects(
+      Test().assert(() => ({ result: false })),
+      e('InteractorError', 'expected assertion to pass but it failed')
+    );
+
+    await assert.rejects(
+      Test().assert(() => ({ result: false, message: 'epic fail' })),
+      e('InteractorError', 'epic fail')
+    );
+  });
+
   it('can be negated with .not', async () => {
     let T = Test.extend({
       assert: {
@@ -33,6 +60,29 @@ describe('InteractorAssert', () => {
       e('InteractorError', 'expected assertion to fail but it passed')
     );
 
+    await assert.doesNotReject(
+      T().assert.not(() => false)
+    );
+
+    await assert.rejects(
+      T().assert.not(() => true),
+      e('InteractorError', 'expected assertion to fail but it passed')
+    );
+
+    await assert.doesNotReject(
+      Test().assert.not(() => ({ result: false }))
+    );
+
+    await assert.rejects(
+      Test().assert.not(() => ({ result: true })),
+      e('InteractorError', 'expected assertion to fail but it passed')
+    );
+
+    await assert.rejects(
+      Test().assert.not(() => ({ result: true, message: 'nega fail' })),
+      e('InteractorError', 'nega fail')
+    );
+
     await assert.doesNotReject(
       T().assert.not(() => {
         throw Error('failed successfully');
@@ -46,9 +96,9 @@ describe('InteractorAssert', () => {
 
     await assert.doesNotReject(
       Test()
-        .assert(() => (delta == null && (delta = 10)))
-        .assert(() => (delta += Date.now() - time))
-        .assert(() => (time = Date.now()))
+        .assert(() => void (delta == null && (delta = 10)))
+        .assert(() => void (delta += Date.now() - time))
+        .assert(() => void (time = Date.now()))
         .assert.remains()
     );