Add support for disabling autoend

Discussion: https://twitter.com/izs/status/958397259418238976
CC: @watson

docs/api/index.md

@@ -34,12 +34,18 @@ slight modifications.
    the main package export.
 3. The test ends automatically when `process.on('exit')` fires, so
    there is no need to call `tap.end()` explicitly.
-4. Adding a `tearDown` function triggers `autoend` behavior.
+4. Adding a `tearDown` function triggers `autoend` behavior, unless
+   `autoend` was explicitly set to `false`.
+
    Otherwise, the `end` would potentially never arrive, if for example
    `tearDown` is used to close a server or cancel some long-running
    process, because `process.on('exit')` would never fire of its own
    accord.
 
+   If you disable `autoend`, and _also_ use a `teardown()` function on
+   the main tap instance, you need to either set a `t.plan(n)` or
+   explicitly call `t.end()` at some point.
+
 ## tap.Test
 
 The `Test` class is the main thing you'll be touching when you use
@@ -229,3 +235,13 @@ Generally, you never need to worry about this directly.
 However, this method can also be called explicitly in cases where an
 error would be handled by something else (for example, a default
 [Promise](/promises/) `.catch(er)` method.)
+
+### t.autoend(value)
+
+If `value` is boolean `false`, then it will disable the `autoend`
+behavior.  If `value` is anything other than `false`, then it will
+cause the test to automatically end when nothing is pending.
+
+Note that this is triggered by default on the root `tap` instance when
+a `teardown()` function is set, unless `autoend` was explicitly
+disabled.

lib/tap.js

@@ -84,7 +84,8 @@ class TAP extends Test {
   // Root test runner doesn't have the 'teardown' event, because it
   // isn't hooked into any parent Test as a harness.
   teardown (fn) {
-    this.autoend()
+    if (this.options.autoend !== false)
+      this.autoend(true)
     return Test.prototype.teardown.apply(this, arguments)
   }
   tearDown (fn) {

lib/test.js

@@ -710,9 +710,15 @@ class Test extends Base {
     return should
   }
 
-  autoend () {
-    this.options.autoend = true
-    this.maybeAutoend()
+  autoend (value) {
+    // set to false to NOT trigger autoend
+    if (value === false) {
+      this.options.autoend = false
+      clearTimeout(this.autoendTimer)
+    } else {
+      this.options.autoend = true
+      this.maybeAutoend()
+    }
   }
 
   maybeAutoend () {

tap-snapshots/test-tap.js-TAP.test.js

@@ -477,3 +477,37 @@ not ok 2 - timeout!
 exports[`test/tap.js TAP timeout sigterm many times > stderr 1`] = `
 
 `
+
+exports[`test/tap.js TAP autoend(false) with teardown > exit status 1`] = `
+{ code: 0, signal: null }
+`
+
+exports[`test/tap.js TAP autoend(false) with teardown > stdout 1`] = `
+TAP version 13
+ok 1 - this is fine
+1..1
+# {time}
+tear it down
+
+`
+
+exports[`test/tap.js TAP autoend(false) with teardown > stderr 1`] = `
+
+`
+
+exports[`test/tap.js TAP autoend=false with teardown > exit status 1`] = `
+{ code: 0, signal: null }
+`
+
+exports[`test/tap.js TAP autoend=false with teardown > stdout 1`] = `
+TAP version 13
+ok 1 - this is fine
+1..1
+# {time}
+tear it down
+
+`
+
+exports[`test/tap.js TAP autoend=false with teardown > stderr 1`] = `
+
+`

tap-snapshots/test-test.js-TAP.test.js

@@ -2142,6 +2142,13 @@ not ok 6 - cannot create subtest after parent test end # {time}
 
 `
 
+exports[`test/test.js TAP assertions and weird stuff autoend(false) > autoend(false) 1`] = `
+TAP version 13
+ok 1 - this is fine
+1..1
+
+`
+
 exports[`test/test.js TAP assertions and weird stuff endAll with test children > endAll with test children 1`] = `
 TAP version 13
 # Subtest: this is the test that never ends

test/tap.js

@@ -103,6 +103,22 @@ const cases = {
     process.kill(process.pid, 'SIGTERM')
     process.kill(process.pid, 'SIGTERM')
   },
+  'autoend(false) with teardown': t => {
+    t.autoend(false)
+    t.teardown(() => console.log('tear it down'))
+    setTimeout(() => {
+      t.pass('this is fine')
+      t.end()
+    }, 50)
+  },
+  'autoend=false with teardown': t => {
+    t.options.autoend = false
+    t.teardown(() => console.log('tear it down'))
+    setTimeout(() => {
+      t.pass('this is fine')
+      t.end()
+    }, 50)
+  },
 }
 
 const main = t => {

test/test.js

@@ -642,6 +642,15 @@ t.test('assertions and weird stuff', t => {
 
     },
 
+    'autoend(false)': tt => {
+      tt.autoend()
+      tt.autoend(false)
+      setTimeout(() => {
+        tt.pass('this is fine')
+        tt.end()
+      }, 50)
+    },
+
     'endAll with test children': tt => {
       tt.test('this is the test that never ends', tt => {
         tt.test('it goes on and on my friend', tt => {