forked from clojure/clojure
-
Notifications
You must be signed in to change notification settings - Fork 12
/
protocols.clj
299 lines (280 loc) · 12.7 KB
/
protocols.clj
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
; Copyright (c) Rich Hickey. All rights reserved.
; The use and distribution terms for this software are covered by the
; Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
; which can be found in the file epl-v10.html at the root of this distribution.
; By using this software in any fashion, you are agreeing to be bound by
; the terms of this license.
; You must not remove this notice, or any other, from this software.
; Author: Stuart Halloway
(ns clojure.test-clojure.protocols
(:use clojure.test clojure.test-clojure.protocols.examples)
(:require [clojure.test-clojure.protocols.more-examples :as other]
clojure.test-clojure.helpers)
(:import [clojure.test_clojure.protocols.examples ExampleInterface]))
;; temporary hack until I decide how to cleanly reload protocol
(defn reload-example-protocols
[]
(alter-var-root #'clojure.test-clojure.protocols.examples/ExampleProtocol
assoc :impls {})
(alter-var-root #'clojure.test-clojure.protocols.more-examples/SimpleProtocol
assoc :impls {})
(require :reload
'clojure.test-clojure.protocols.examples
'clojure.test-clojure.protocols.more-examples))
(defn method-names
"return sorted list of method names on a class"
[c]
(->> (.getMethods c)
(map #(.getName %))
(sort)))
(defrecord EmptyRecord [])
(defrecord TestRecord [a b])
(defn r
([a b] (TestRecord. a b))
([a b meta ext] (TestRecord. a b meta ext)))
(defrecord MapEntry [k v]
java.util.Map$Entry
(getKey [_] k)
(getValue [_] v))
(deftest protocols-test
(testing "protocol fns have useful metadata"
(let [common-meta {:ns (find-ns 'clojure.test-clojure.protocols.examples)
:protocol #'ExampleProtocol}]
(are [m f] (= (merge (quote m) common-meta)
(meta (var f)))
{:name foo :arglists ([a]) :doc "method with one arg"} foo
{:name bar :arglists ([a b]) :doc "method with two args"} bar
{:name baz :arglists ([a] [a b]) :doc "method with multiple arities" :tag String} baz
{:name with-quux :arglists ([a]) :doc "method name with a hyphen"} with-quux)))
(testing "protocol fns throw IllegalArgumentException if no impl matches"
(is (thrown-with-msg?
IllegalArgumentException
#"No implementation of method: :foo of protocol: #'clojure.test-clojure.protocols.examples/ExampleProtocol found for class: java.lang.Integer"
(foo 10))))
(testing "protocols generate a corresponding interface using _ instead of - for method names"
(is (= ["bar" "baz" "baz" "foo" "with_quux"] (method-names clojure.test_clojure.protocols.examples.ExampleProtocol))))
(testing "protocol will work with instances of its interface (use for interop, not in Clojure!)"
(let [obj (proxy [clojure.test_clojure.protocols.examples.ExampleProtocol] []
(foo [] "foo!"))]
(is (= "foo!" (.foo obj)) "call through interface")
(is (= "foo!" (foo obj)) "call through protocol")))
(testing "you can implement just part of a protocol if you want"
(let [obj (reify ExampleProtocol
(baz [a b] "two-arg baz!"))]
(is (= "two-arg baz!" (baz obj nil)))
(is (thrown? AbstractMethodError (baz obj)))))
(testing "you can redefine a protocol with different methods"
(eval '(defprotocol Elusive (old-method [x])))
(eval '(defprotocol Elusive (new-method [x])))
(is (= :new-method (eval '(new-method (reify Elusive (new-method [x] :new-method))))))
(is (fails-with-cause? IllegalArgumentException #"No method of interface: user\.Elusive found for function: old-method of protocol: Elusive \(The protocol method may have been defined before and removed\.\)"
(eval '(old-method (reify Elusive (new-method [x] :new-method))))))))
(deftype ExtendTestWidget [name])
(deftype HasProtocolInline []
ExampleProtocol
(foo [this] :inline))
(deftest extend-test
(testing "you can extend a protocol to a class"
(extend String ExampleProtocol
{:foo identity})
(is (= "pow" (foo "pow"))))
(testing "you can have two methods with the same name. Just use namespaces!"
(extend String other/SimpleProtocol
{:foo (fn [s] (.toUpperCase s))})
(is (= "POW" (other/foo "pow"))))
(testing "you can extend deftype types"
(extend
ExtendTestWidget
ExampleProtocol
{:foo (fn [this] (str "widget " (.name this)))})
(is (= "widget z" (foo (ExtendTestWidget. "z"))))))
(deftest illegal-extending
(testing "you cannot extend a protocol to a type that implements the protocol inline"
(is (fails-with-cause? IllegalArgumentException #".*HasProtocolInline already directly implements interface"
(eval '(extend clojure.test-clojure.protocols.HasProtocolInline
clojure.test-clojure.protocols.examples/ExampleProtocol
{:foo (fn [_] :extended)})))))
(testing "you cannot extend to an interface"
(is (fails-with-cause? IllegalArgumentException #"interface clojure.test_clojure.protocols.examples.ExampleProtocol is not a protocol"
(eval '(extend clojure.test-clojure.protocols.HasProtocolInline
clojure.test_clojure.protocols.examples.ExampleProtocol
{:foo (fn [_] :extended)}))))))
(deftype ExtendsTestWidget []
ExampleProtocol)
(deftest extends?-test
(reload-example-protocols)
(testing "returns false if a type does not implement the protocol at all"
(is (false? (extends? other/SimpleProtocol ExtendsTestWidget))))
(testing "returns true if a type implements the protocol directly" ;; semantics changed 4/15/2010
(is (true? (extends? ExampleProtocol ExtendsTestWidget))))
(testing "returns true if a type explicitly extends protocol"
(extend
ExtendsTestWidget
other/SimpleProtocol
{:foo identity})
(is (true? (extends? other/SimpleProtocol ExtendsTestWidget)))))
(deftype ExtendersTestWidget [])
(deftest extenders-test
(reload-example-protocols)
(testing "a fresh protocol has no extenders"
(is (nil? (extenders ExampleProtocol))))
(testing "extending with no methods doesn't count!"
(deftype Something [])
(extend ::Something ExampleProtocol)
(is (nil? (extenders ExampleProtocol))))
(testing "extending a protocol (and including an impl) adds an entry to extenders"
(extend ExtendersTestWidget ExampleProtocol {:foo identity})
(is (= [ExtendersTestWidget] (extenders ExampleProtocol)))))
(deftype SatisfiesTestWidget []
ExampleProtocol)
(deftest satisifies?-test
(reload-example-protocols)
(let [whatzit (SatisfiesTestWidget.)]
(testing "returns false if a type does not implement the protocol at all"
(is (false? (satisfies? other/SimpleProtocol whatzit))))
(testing "returns true if a type implements the protocol directly"
(is (true? (satisfies? ExampleProtocol whatzit))))
(testing "returns true if a type explicitly extends protocol"
(extend
SatisfiesTestWidget
other/SimpleProtocol
{:foo identity})
(is (true? (satisfies? other/SimpleProtocol whatzit))))) )
(deftype ReExtendingTestWidget [])
(deftest re-extending-test
(reload-example-protocols)
(extend
ReExtendingTestWidget
ExampleProtocol
{:foo (fn [_] "first foo")
:baz (fn [_] "first baz")})
(testing "if you re-extend, the old implementation is replaced (not merged!)"
(extend
ReExtendingTestWidget
ExampleProtocol
{:baz (fn [_] "second baz")
:bar (fn [_ _] "second bar")})
(let [whatzit (ReExtendingTestWidget.)]
(is (thrown? IllegalArgumentException (foo whatzit)))
(is (= "second bar" (bar whatzit nil)))
(is (= "second baz" (baz whatzit))))))
(defrecord DefrecordObjectMethodsWidgetA [a])
(defrecord DefrecordObjectMethodsWidgetB [a])
(deftest defrecord-object-methods-test
(testing ".equals depends on fields and type"
(is (true? (.equals (DefrecordObjectMethodsWidgetA. 1) (DefrecordObjectMethodsWidgetA. 1))))
(is (false? (.equals (DefrecordObjectMethodsWidgetA. 1) (DefrecordObjectMethodsWidgetA. 2))))
(is (false? (.equals (DefrecordObjectMethodsWidgetA. 1) (DefrecordObjectMethodsWidgetB. 1)))))
(testing ".hashCode depends on fields and type"
(is (= (.hashCode (DefrecordObjectMethodsWidgetA. 1)) (.hashCode (DefrecordObjectMethodsWidgetA. 1))))
(is (= (.hashCode (DefrecordObjectMethodsWidgetA. 2)) (.hashCode (DefrecordObjectMethodsWidgetA. 2))))
(is (not= (.hashCode (DefrecordObjectMethodsWidgetA. 1)) (.hashCode (DefrecordObjectMethodsWidgetA. 2))))
(is (= (.hashCode (DefrecordObjectMethodsWidgetB. 1)) (.hashCode (DefrecordObjectMethodsWidgetB. 1))))
(is (not= (.hashCode (DefrecordObjectMethodsWidgetA. 1)) (.hashCode (DefrecordObjectMethodsWidgetB. 1))))))
(deftest defrecord-acts-like-a-map
(let [rec (r 1 2)]
(is (= (r 1 3 {} {:c 4}) (merge rec {:b 3 :c 4})))
(is (= {:a 11 :b 2 :c 10} (merge-with + rec {:a 10 :c 10})))))
(deftest defrecord-interfaces-test
(testing "java.util.Map"
(let [rec (r 1 2)]
(is (= 2 (.size rec)))
(is (= 3 (.size (assoc rec :c 3))))
(is (not (.isEmpty rec)))
(is (.isEmpty (EmptyRecord.)))
(is (.containsKey rec :a))
(is (not (.containsKey rec :c)))
(is (.containsValue rec 1))
(is (not (.containsValue rec 3)))
(is (= 1 (.get rec :a)))
(is (thrown? UnsupportedOperationException (.put rec :a 1)))
(is (thrown? UnsupportedOperationException (.remove rec :a)))
(is (thrown? UnsupportedOperationException (.putAll rec {})))
(is (thrown? UnsupportedOperationException (.clear rec)))
(is (= #{:a :b} (.keySet rec)))
(is (= #{1 2} (set (.values rec))))
(is (= #{[:a 1] [:b 2]} (.entrySet rec)))
))
(testing "IPersistentCollection"
(testing ".cons"
(let [rec (r 1 2)]
(are [x] (= rec (.cons rec x))
nil {})
(is (= (r 1 3) (.cons rec {:b 3})))
(is (= (r 1 4) (.cons rec [:b 4])))
(is (= (r 1 5) (.cons rec (MapEntry. :b 5))))))))
(defrecord RecordWithSpecificFieldNames [this that k m o])
(deftest defrecord-with-specific-field-names
(let [rec (new RecordWithSpecificFieldNames 1 2 3 4 5)]
(is (= rec rec))
(is (= 1 (:this (with-meta rec {:foo :bar}))))
(is (= 3 (get rec :k)))
(is (= (seq rec) '([:this 1] [:that 2] [:k 3] [:m 4] [:o 5])))
(is (= (dissoc rec :k) {:this 1, :that 2, :m 4, :o 5}))))
(deftest reify-test
(testing "of an interface"
(let [s :foo
r (reify
java.util.List
(contains [_ o] (= s o)))]
(testing "implemented methods"
(is (true? (.contains r :foo)))
(is (false? (.contains r :bar))))
(testing "unimplemented methods"
(is (thrown? AbstractMethodError (.add r :baz))))))
(testing "of two interfaces"
(let [r (reify
java.util.List
(contains [_ o] (= :foo o))
java.util.Collection
(isEmpty [_] false))]
(is (true? (.contains r :foo)))
(is (false? (.contains r :bar)))
(is (false? (.isEmpty r)))))
(testing "you can't define a method twice"
(is (fails-with-cause?
java.lang.ClassFormatError #"^(Repetitive|Duplicate) method name"
(eval '(reify
java.util.List
(size [_] 10)
java.util.Collection
(size [_] 20))))))
(testing "you can't define a method not on an interface/protocol/j.l.Object"
(is (fails-with-cause?
IllegalArgumentException #"^Can't define method not in interfaces: foo"
(eval '(reify java.util.List (foo [_]))))))
(testing "of a protocol"
(let [r (reify
ExampleProtocol
(bar [this o] o)
(baz [this] 1)
(baz [this o] 2))]
(= :foo (.bar r :foo))
(= 1 (.baz r))
(= 2 (.baz r nil))))
(testing "destructuring in method def"
(let [r (reify
ExampleProtocol
(bar [this [_ _ item]] item))]
(= :c (.bar r [:a :b :c]))))
(testing "methods can recur"
(let [r (reify
java.util.List
(get [_ index]
(if (zero? index)
:done
(recur (dec index)))))]
(is (= :done (.get r 0)))
(is (= :done (.get r 1)))))
(testing "disambiguating with type hints"
(testing "you must hint an overloaded method"
(is (fails-with-cause?
IllegalArgumentException #"Must hint overloaded method: hinted"
(eval '(reify clojure.test_clojure.protocols.examples.ExampleInterface (hinted [_ o]))))))
(testing "hinting"
(let [r (reify
ExampleInterface
(hinted [_ ^int i] (inc i))
(hinted [_ ^String s] (str s s)))]
(is (= 2 (.hinted r 1)))
(is (= "xoxo" (.hinted r "xo")))))))