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-rw-r--r--spec/util_promise_spec.lua261
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diff --git a/spec/util_promise_spec.lua b/spec/util_promise_spec.lua
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+local promise = require "util.promise";
+
+describe("util.promise", function ()
+ --luacheck: ignore 212/resolve 212/reject
+ describe("new()", function ()
+ it("returns a promise object", function ()
+ assert(promise.new());
+ end);
+ end);
+ it("notifies immediately for fulfilled promises", function ()
+ local p = promise.new(function (resolve)
+ resolve("foo");
+ end);
+ local cb = spy.new(function (v)
+ assert.equal("foo", v);
+ end);
+ p:next(cb);
+ assert.spy(cb).was_called(1);
+ end);
+ it("notifies on fulfilment of pending promises", function ()
+ local r;
+ local p = promise.new(function (resolve)
+ r = resolve;
+ end);
+ local cb = spy.new(function (v)
+ assert.equal("foo", v);
+ end);
+ p:next(cb);
+ assert.spy(cb).was_called(0);
+ r("foo");
+ assert.spy(cb).was_called(1);
+ end);
+ it("allows chaining :next() calls", function ()
+ local r;
+ local result;
+ local p = promise.new(function (resolve)
+ r = resolve;
+ end);
+ local cb1 = spy.new(function (v)
+ assert.equal("foo", v);
+ return "bar";
+ end);
+ local cb2 = spy.new(function (v)
+ assert.equal("bar", v);
+ result = v;
+ end);
+ p:next(cb1):next(cb2);
+ assert.spy(cb1).was_called(0);
+ assert.spy(cb2).was_called(0);
+ r("foo");
+ assert.spy(cb1).was_called(1);
+ assert.spy(cb2).was_called(1);
+ assert.equal("bar", result);
+ end);
+ it("supports multiple :next() calls on the same promise", function ()
+ local r;
+ local result;
+ local p = promise.new(function (resolve)
+ r = resolve;
+ end);
+ local cb1 = spy.new(function (v)
+ assert.equal("foo", v);
+ result = v;
+ end);
+ local cb2 = spy.new(function (v)
+ assert.equal("foo", v);
+ result = v;
+ end);
+ p:next(cb1);
+ p:next(cb2);
+ assert.spy(cb1).was_called(0);
+ assert.spy(cb2).was_called(0);
+ r("foo");
+ assert.spy(cb1).was_called(1);
+ assert.spy(cb2).was_called(1);
+ assert.equal("foo", result);
+ end);
+ it("automatically rejects on error", function ()
+ local r;
+ local p = promise.new(function (resolve)
+ r = resolve;
+ error("oh no");
+ end);
+ local cb = spy.new(function () end);
+ local err_cb = spy.new(function (v)
+ assert.equal("oh no", v);
+ end);
+ p:next(cb, err_cb);
+ assert.spy(cb).was_called(0);
+ assert.spy(err_cb).was_called(1);
+ r("foo");
+ assert.spy(cb).was_called(0);
+ assert.spy(err_cb).was_called(1);
+ end);
+ it("supports reject()", function ()
+ local r, result;
+ local p = promise.new(function (resolve, reject)
+ r = reject;
+ end);
+ local cb = spy.new(function () end);
+ local err_cb = spy.new(function (v)
+ result = v;
+ assert.equal("oh doh", v);
+ end);
+ p:next(cb, err_cb);
+ assert.spy(cb).was_called(0);
+ assert.spy(err_cb).was_called(0);
+ r("oh doh");
+ assert.spy(cb).was_called(0);
+ assert.spy(err_cb).was_called(1);
+ assert.equal("oh doh", result);
+ end);
+ it("supports chaining of rejected promises", function ()
+ local r, result;
+ local p = promise.new(function (resolve, reject)
+ r = reject;
+ end);
+ local cb = spy.new(function () end);
+ local err_cb = spy.new(function (v)
+ result = v;
+ assert.equal("oh doh", v);
+ return "ok"
+ end);
+ local cb2 = spy.new(function (v)
+ result = v;
+ end);
+ local err_cb2 = spy.new(function () end);
+ p:next(cb, err_cb):next(cb2, err_cb2)
+ assert.spy(cb).was_called(0);
+ assert.spy(err_cb).was_called(0);
+ assert.spy(cb2).was_called(0);
+ assert.spy(err_cb2).was_called(0);
+ r("oh doh");
+ assert.spy(cb).was_called(0);
+ assert.spy(err_cb).was_called(1);
+ assert.spy(cb2).was_called(1);
+ assert.spy(err_cb2).was_called(0);
+ assert.equal("ok", result);
+ end);
+
+ describe("race()", function ()
+ it("works with fulfilled promises", function ()
+ local p1, p2 = promise.resolve("yep"), promise.resolve("nope");
+ local p = promise.race({ p1, p2 });
+ local result;
+ p:next(function (v)
+ result = v;
+ end);
+ assert.equal("yep", result);
+ end);
+ it("works with pending promises", function ()
+ local r1, r2;
+ local p1, p2 = promise.new(function (resolve) r1 = resolve end), promise.new(function (resolve) r2 = resolve end);
+ local p = promise.race({ p1, p2 });
+
+ local result;
+ local cb = spy.new(function (v)
+ result = v;
+ end);
+ p:next(cb);
+ assert.spy(cb).was_called(0);
+ r2("yep");
+ r1("nope");
+ assert.spy(cb).was_called(1);
+ assert.equal("yep", result);
+ end);
+ end);
+ describe("all()", function ()
+ it("works with fulfilled promises", function ()
+ local p1, p2 = promise.resolve("yep"), promise.resolve("nope");
+ local p = promise.all({ p1, p2 });
+ local result;
+ p:next(function (v)
+ result = v;
+ end);
+ assert.same({ "yep", "nope" }, result);
+ end);
+ it("works with pending promises", function ()
+ local r1, r2;
+ local p1, p2 = promise.new(function (resolve) r1 = resolve end), promise.new(function (resolve) r2 = resolve end);
+ local p = promise.all({ p1, p2 });
+
+ local result;
+ local cb = spy.new(function (v)
+ result = v;
+ end);
+ p:next(cb);
+ assert.spy(cb).was_called(0);
+ r2("yep");
+ assert.spy(cb).was_called(0);
+ r1("nope");
+ assert.spy(cb).was_called(1);
+ assert.same({ "nope", "yep" }, result);
+ end);
+ it("rejects if any promise rejects", function ()
+ local r1, r2;
+ local p1 = promise.new(function (resolve, reject) r1 = reject end);
+ local p2 = promise.new(function (resolve, reject) r2 = reject end);
+ local p = promise.all({ p1, p2 });
+
+ local result;
+ local cb = spy.new(function (v)
+ result = v;
+ end);
+ local cb_err = spy.new(function (v)
+ result = v;
+ end);
+ p:next(cb, cb_err);
+ assert.spy(cb).was_called(0);
+ assert.spy(cb_err).was_called(0);
+ r2("fail");
+ assert.spy(cb).was_called(0);
+ assert.spy(cb_err).was_called(1);
+ r1("nope");
+ assert.spy(cb).was_called(0);
+ assert.spy(cb_err).was_called(1);
+ assert.equal("fail", result);
+ end);
+ end);
+ describe("catch()", function ()
+ it("works", function ()
+ local result;
+ local p = promise.new(function (resolve)
+ error({ foo = true });
+ end);
+ local cb1 = spy.new(function (v)
+ result = v;
+ end);
+ assert.spy(cb1).was_called(0);
+ p:catch(cb1);
+ assert.spy(cb1).was_called(1);
+ assert.same({ foo = true }, result);
+ end);
+ end);
+ it("promises may be resolved by other promises", function ()
+ local r1, r2;
+ local p1, p2 = promise.new(function (resolve) r1 = resolve end), promise.new(function (resolve) r2 = resolve end);
+
+ local result;
+ local cb = spy.new(function (v)
+ result = v;
+ end);
+ p1:next(cb);
+ assert.spy(cb).was_called(0);
+
+ r1(p2);
+ assert.spy(cb).was_called(0);
+ r2("yep");
+ assert.spy(cb).was_called(1);
+ assert.equal("yep", result);
+ end);
+ describe("reject()", function ()
+ it("returns a rejected promise", function ()
+ local p = promise.reject("foo");
+ local cb = spy.new(function () end);
+ p:next(cb);
+ assert.spy(cb).was_called(1);
+ assert.spy(cb).was_called_with("foo");
+ end);
+ end);
+end);