polyfill for assert.rejects

rmdm · Sep 26, 2018 · c33aa79 · c33aa79
1 parent b4542b2
commit c33aa79
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Showing 2 changed files with 21 additions and 8 deletions.
diff --git a/.travis.yml b/.travis.yml
@@ -2,8 +2,6 @@ language: node_js
 node_js:
   - "10.11"
   - "8.11"
-  - "6.1"
-  - "4.4"
 
 script: "npm run ci"
 after_script: "cat ./coverage/lcov.info | coveralls"
diff --git a/test/promback.spec.js b/test/promback.spec.js
@@ -37,11 +37,11 @@ function testUsing (contextTitle, promiseLib) {
 
             it('rejects when passed function throws', async function () {
 
-                const err = new Error()
+                const err = new Error('an error')
 
                 const fn = promback(function () { throw err })
 
-                await assert.rejects(function () {
+                await assertRejects(function () {
                     return fn()
                 }, function (e) {
                     return err === e
@@ -50,11 +50,11 @@ function testUsing (contextTitle, promiseLib) {
 
             it('rejects when passed function rejects', async function () {
 
-                const err = new Error()
+                const err = new Error('an error')
 
                 const fn = promback(function () { return Promise.reject(err) })
 
-                await assert.rejects(function () {
+                await assertRejects(function () {
                     return fn()
                 }, function (e) {
                     return err === e
@@ -64,13 +64,13 @@ function testUsing (contextTitle, promiseLib) {
             it('rejects when passed function calls callback with an error',
                 async function () {
 
-                const err = new Error()
+                const err = new Error('an error')
 
                 const fn = promback(function (cb) {
                     cb(err)
                 })
 
-                await assert.rejects(function () {
+                await assertRejects(function () {
                     return fn()
                 }, function (e) {
                     return err === e
@@ -153,3 +153,18 @@ function testUsing (contextTitle, promiseLib) {
         })
     })
 }
+
+async function assertRejects (rejecter, predicate) {
+
+    if (assert.rejects) {
+        return assert.rejects(rejecter, predicate)
+    }
+
+    try {
+        await rejecter()
+        throw new Error('Rejection expected.')
+    } catch (err) {
+        if (predicate(err)) { return }
+        throw err
+    }
+}