|
|
@@ -1,500 +1,29 @@
|
|
1
|
|
-NOTE: You can also view the HTML version of this file here:
|
|
2
|
|
-https://github.com/exercism/xjava/blob/master/exercises/hello-world/GETTING_STARTED.md
|
|
3
|
|
-
|
|
4
|
|
-* [Solving "Hello, World!"](#solving-hello-world)
|
|
5
|
|
- * [Reading Gradle output](#reading-gradle-output)
|
|
6
|
|
- * [Fixing the first failing test](#fixing-the-first-failing-test)
|
|
7
|
|
- * [Enabling and fixing the second test](#enabling-and-fixing-the-second-test)
|
|
8
|
|
- * [Enabling the last test](#enabling-the-last-test)
|
|
9
|
|
- * [Refactoring](#refactoring)
|
|
10
|
|
-* [Submitting your first iteration](#submitting-your-first-iteration)
|
|
11
|
|
-* [Next Steps](#next-steps)
|
|
12
|
|
- * [Review (and comment on) others' submissions to this exercise](#review-and-comment-on-others-submissions-to-this-exercise)
|
|
13
|
|
- * [Extend an exercise](#extend-an-exercise)
|
|
14
|
|
-
|
|
15
|
|
-----
|
|
16
|
|
-
|
|
17
|
|
-# Solving "Hello, World!"
|
|
18
|
|
-
|
|
19
|
|
-Welcome to the first exercise on the Java track!
|
|
20
|
|
-
|
|
21
|
|
-This is a step-by-step guide to solving this exercise.
|
|
22
|
|
-
|
|
23
|
|
-Each exercise comes with a set of tests. The first pass through the
|
|
24
|
|
-exercise is about getting all of the tests to pass, one at a time.
|
|
25
|
|
-
|
|
26
|
|
-If you have not installed the Java Development Kit and Gradle, you must do
|
|
27
|
|
-so now. For help with this, see: http://exercism.io/languages/java/installing
|
|
28
|
|
-
|
|
29
|
1
|
----
|
|
|
2
|
+# Quick Start Guide
|
|
30
|
3
|
|
|
31
|
4
|
This guide picks-up where [Running the Tests (in Java)](http://exercism.io/languages/java/tests)
|
|
32
|
5
|
left off. If you haven't reviewed those instructions, do so now.
|
|
33
|
6
|
|
|
34
|
|
-The following instructions work equally well on Windows, Mac OS X and Linux.
|
|
35
|
|
-
|
|
36
|
|
-## Reading Gradle output
|
|
37
|
|
-
|
|
38
|
|
-Use Gradle to run the tests:
|
|
39
|
|
-
|
|
40
|
|
-```
|
|
41
|
|
-$ gradle test
|
|
42
|
|
-```
|
|
43
|
|
-
|
|
44
|
|
-This command does a lot and displays a bunch of stuff. Let's break it down...
|
|
45
|
|
-
|
|
46
|
|
-```
|
|
47
|
|
-:compileJava
|
|
48
|
|
-:processResources UP-TO-DATE
|
|
49
|
|
-:classes
|
|
50
|
|
-```
|
|
51
|
|
-
|
|
52
|
|
-Each line that begins with a colon (like `:compileJava`) is Gradle telling
|
|
53
|
|
-us that it's starting that task. The first three tasks are about compiling
|
|
54
|
|
-the source code of our *solution*. We've done you a favor and included just
|
|
55
|
|
-enough code for the solution that it compiles.
|
|
56
|
|
-
|
|
57
|
|
-When a task is successful, it generally does not output anything. This is
|
|
58
|
|
-why `:compileJava` and `:classes` do not produce any additional output.
|
|
59
|
|
-`:processResources` reports that it had nothing to do.
|
|
60
|
|
-
|
|
61
|
|
-So far, so good...
|
|
62
|
|
-
|
|
63
|
|
-The next three tasks are about compiling source code of the *tests*.
|
|
64
|
|
-
|
|
65
|
|
-```
|
|
66
|
|
-:compileTestJava
|
|
67
|
|
-:processTestResources UP-TO-DATE
|
|
68
|
|
-:testClasses
|
|
69
|
|
-```
|
|
70
|
|
-
|
|
71
|
|
-... with both sets of source code successfully compiled, Gradle turns to
|
|
72
|
|
-running the task you asked it to: executing the tests against the solution.
|
|
73
|
|
-
|
|
74
|
|
-```
|
|
75
|
|
-:test
|
|
76
|
|
-
|
|
77
|
|
-HelloWorldTest > helloNoName FAILED
|
|
78
|
|
- java.lang.AssertionError: expected:<Hello, World!> but was:<null>
|
|
79
|
|
- at org.junit.Assert.fail(Assert.java:93)
|
|
80
|
|
- at org.junit.Assert.failNotEquals(Assert.java:647)
|
|
81
|
|
- at org.junit.Assert.assertEquals(Assert.java:128)
|
|
82
|
|
- at org.junit.Assert.assertEquals(Assert.java:147)
|
|
83
|
|
- at HelloWorldTest.helloNoName(HelloWorldTest.java:10)
|
|
84
|
|
-
|
|
85
|
|
-HelloWorldTest > helloSampleName SKIPPED
|
|
86
|
|
-
|
|
87
|
|
-HelloWorldTest > helloAnotherSampleName SKIPPED
|
|
88
|
|
-
|
|
89
|
|
-3 tests completed, 1 failed, 2 skipped
|
|
90
|
|
-:test FAILED
|
|
91
|
|
-
|
|
92
|
|
-FAILURE: Build failed with an exception.
|
|
93
|
|
-
|
|
94
|
|
-* What went wrong:
|
|
95
|
|
-Execution failed for task ':test'.
|
|
96
|
|
-> There were failing tests. See the report at: file:///Users/jtigger/projects/exercism/xjava/build/exercism/java/hello-world/build/reports/tests/index.html
|
|
97
|
|
-
|
|
98
|
|
-* Try:
|
|
99
|
|
-Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
|
|
100
|
|
-
|
|
101
|
|
-BUILD FAILED
|
|
102
|
|
-
|
|
103
|
|
-Total time: 6.716 secs
|
|
104
|
|
-```
|
|
105
|
|
-
|
|
106
|
|
-Seeing the word "fail" TEN TIMES might give you the impression you've done
|
|
107
|
|
-something horribly wrong. You haven't. It's a whole lot of noise over
|
|
108
|
|
-a single test not passing.
|
|
109
|
|
-
|
|
110
|
|
-Let's focus in on the important bits:
|
|
111
|
|
-
|
|
112
|
|
-```
|
|
113
|
|
-HelloWorldTest > helloNoName FAILED
|
|
114
|
|
- java.lang.AssertionError: expected:<Hello, World!> but was:<null>
|
|
115
|
|
-```
|
|
116
|
|
-
|
|
117
|
|
-...is read: "Within the test class named `HelloWorldTest`, the test method
|
|
118
|
|
-`helloNoName` did not pass because the solution did not satisfy an
|
|
119
|
|
-assertion. Apparently, we expected to see the string 'Hello, World!' but
|
|
120
|
|
-the value `null` was returned instead.
|
|
121
|
|
-
|
|
122
|
|
-The last line of the stack trace tells us exactly where this unsatisfied
|
|
123
|
|
-assertion lives:
|
|
124
|
|
-
|
|
125
|
|
-```
|
|
126
|
|
- at HelloWorldTest.helloNoName(HelloWorldTest.java:10)
|
|
127
|
|
-```
|
|
128
|
|
-
|
|
129
|
|
-Looks like the crime was discovered on line 10 in the test file.
|
|
130
|
|
-
|
|
131
|
|
-Knowing these two facts,
|
|
132
|
|
-
|
|
133
|
|
-1. the return value was not what was expected, and
|
|
134
|
|
-2. the failure was on line 10 of the test,
|
|
135
|
|
-
|
|
136
|
|
-we can turn this failure into success.
|
|
137
|
|
-
|
|
138
|
|
-
|
|
139
|
|
-
|
|
140
|
|
-## Fixing the first failing test
|
|
141
|
|
-
|
|
142
|
|
-In your favorite text editor, open `src/test/java/HelloWorldTest.java`
|
|
143
|
|
-and go to line 10.
|
|
144
|
|
-
|
|
145
|
|
-```java
|
|
146
|
|
-assertEquals("Hello, World!", HelloWorld.hello(""));
|
|
147
|
|
-```
|
|
148
|
|
-
|
|
149
|
|
-The test is expecting that `hello()`, when given an empty string (`""`),
|
|
150
|
|
-returns "Hello, World!". Instead, `hello()` is returning `null`.
|
|
151
|
|
-Let's fix that.
|
|
152
|
|
-
|
|
153
|
|
-Open `src/main/java/HelloWorld.java`.
|
|
154
|
|
-
|
|
155
|
|
-```java
|
|
156
|
|
-public class HelloWorld {
|
|
157
|
|
- public static String hello(String name) {
|
|
158
|
|
- return null;
|
|
159
|
|
- }
|
|
160
|
|
-}
|
|
161
|
|
-```
|
|
162
|
|
-
|
|
163
|
|
-Let's change that to return the expected string:
|
|
164
|
|
-
|
|
165
|
|
-```java
|
|
166
|
|
-public class HelloWorld {
|
|
167
|
|
- public static String hello(String name) {
|
|
168
|
|
- return "Hello, World!";
|
|
169
|
|
- }
|
|
170
|
|
-}
|
|
171
|
|
-```
|
|
172
|
|
-
|
|
173
|
|
-Save the file and run the tests again:
|
|
174
|
|
-
|
|
175
|
|
-```
|
|
176
|
|
-$ gradle test
|
|
177
|
|
-:compileJava
|
|
178
|
|
-:processResources UP-TO-DATE
|
|
179
|
|
-:classes
|
|
180
|
|
-:compileTestJava
|
|
181
|
|
-:processTestResources UP-TO-DATE
|
|
182
|
|
-:testClasses
|
|
183
|
|
-:test
|
|
184
|
|
-
|
|
185
|
|
-HelloWorldTest > helloAnotherSampleName SKIPPED
|
|
186
|
|
-
|
|
187
|
|
-HelloWorldTest > helloNoName PASSED
|
|
188
|
|
-
|
|
189
|
|
-HelloWorldTest > helloSampleName SKIPPED
|
|
190
|
|
-
|
|
191
|
|
-BUILD SUCCESSFUL
|
|
192
|
|
-
|
|
193
|
|
-Total time: 4.523 secs
|
|
194
|
|
-```
|
|
195
|
|
-
|
|
196
|
|
-"BUILD SUCCESSFUL"! Woohoo! :) You can see that `helloNoName()` test is
|
|
197
|
|
-now passing.
|
|
198
|
|
-
|
|
199
|
|
-With one win under our belt, we can turn our focus to some other messages
|
|
200
|
|
-that we've been ignoring: the lines ending in "`SKIPPED`".
|
|
201
|
|
-
|
|
202
|
|
-Each test suite contains a series of tests, all of which have been marked
|
|
203
|
|
-to be skipped/ignored except the first one. We did this to help you focus
|
|
204
|
|
-on getting one test running at a time.
|
|
205
|
|
-
|
|
206
|
|
-Let's tackle the next test...
|
|
207
|
|
-
|
|
208
|
|
-
|
|
209
|
|
-
|
|
210
|
|
-## Enabling and fixing the second test
|
|
211
|
|
-
|
|
212
|
|
-Right now, that second test is being skipped/ignored. Let's enable it.
|
|
213
|
|
-
|
|
214
|
|
-(Re)open `src/test/java/HelloWorldTest.java` and find the second test:
|
|
215
|
|
-
|
|
216
|
|
-```java
|
|
217
|
|
-...
|
|
218
|
|
-@Test
|
|
219
|
|
-@Ignore
|
|
220
|
|
-public void helloSampleName() {
|
|
221
|
|
- assertEquals("Hello, Alice!", HelloWorld.hello("Alice"));
|
|
222
|
|
-}
|
|
223
|
|
-...
|
|
224
|
|
-```
|
|
225
|
|
-
|
|
226
|
|
-When the JUnit test runner sees that `@Ignore` annotation on the test
|
|
227
|
|
-method, it knows to skip over that test. Remove that line:
|
|
228
|
|
-
|
|
229
|
|
-```java
|
|
230
|
|
-...
|
|
231
|
|
-@Test
|
|
232
|
|
-public void helloSampleName() {
|
|
233
|
|
- assertEquals("Hello, Alice!", HelloWorld.hello("Alice"));
|
|
234
|
|
-}
|
|
235
|
|
-...
|
|
236
|
|
-```
|
|
237
|
|
-
|
|
238
|
|
-Now, when you run the tests, both tests run:
|
|
239
|
|
-
|
|
240
|
|
-```sh
|
|
241
|
|
-$ gradle test
|
|
242
|
|
-...
|
|
243
|
|
-:test
|
|
244
|
|
-
|
|
245
|
|
-HelloWorldTest > helloNoName PASSED
|
|
246
|
|
-
|
|
247
|
|
-HelloWorldTest > helloSampleName FAILED
|
|
248
|
|
- org.junit.ComparisonFailure: expected:<Hello, [Alice]!> but was:<Hello, [World]!>
|
|
249
|
|
- at org.junit.Assert.assertEquals(Assert.java:125)
|
|
250
|
|
- at org.junit.Assert.assertEquals(Assert.java:147)
|
|
251
|
|
- at HelloWorldTest.helloSampleName(HelloWorldTest.java:16)
|
|
252
|
|
-
|
|
253
|
|
-HelloWorldTest > helloAnotherSampleName SKIPPED
|
|
254
|
|
-
|
|
255
|
|
-3 tests completed, 1 failed, 1 skipped
|
|
256
|
|
-...
|
|
257
|
|
-```
|
|
258
|
|
-
|
|
259
|
|
-The first test, `helloNoName()` continues to pass. We see that
|
|
260
|
|
-`helloSampleName` -- the test we just un-`@Ignore`'d -- is now running and
|
|
261
|
|
-failing. Yay, failing test! In fact, the "failure" message is just
|
|
262
|
|
-describing the difference between what the program does now and what it
|
|
263
|
|
-should do for us to call it "done."
|
|
|
7
|
+Need more information? A **step-by-step tutorial** is available in this directory at TUTORIAL.md or you can read
|
|
|
8
|
+the [HTML version](https://github.com/exercism/xjava/blob/master/exercises/hello-world/TUTORIAL.md).
|
|
264
|
9
|
|
|
265
|
|
-Right now, we've hardcoded the greeting. Enabling this second test has
|
|
266
|
|
-unleashed a new expectation: that our program incorporate a name given
|
|
267
|
|
-into that greeting. When given the name "`Alice`", that's who should be
|
|
268
|
|
-greeted instead of "`World`".
|
|
269
|
|
-
|
|
270
|
|
-(Re)open `src/main/java/HelloWorld.java`.
|
|
271
|
|
-
|
|
272
|
|
-```java
|
|
273
|
|
-public class HelloWorld {
|
|
274
|
|
- public static String hello(String name) {
|
|
275
|
|
- return "Hello, World!";
|
|
276
|
|
- }
|
|
277
|
|
-}
|
|
278
|
|
-```
|
|
279
|
|
-
|
|
280
|
|
-While `hello()` does accept a reference to a string named `name`, it is not
|
|
281
|
|
-using it in the output. Let's change that:
|
|
282
|
|
-
|
|
283
|
|
-
|
|
284
|
|
-```java
|
|
285
|
|
-public class HelloWorld {
|
|
286
|
|
- public static String hello(String name) {
|
|
287
|
|
- return "Hello, " + name + "!";
|
|
288
|
|
- }
|
|
289
|
|
-}
|
|
290
|
|
-```
|
|
291
|
|
-
|
|
292
|
|
-... and rerun the tests ...
|
|
293
|
|
-
|
|
294
|
|
-```
|
|
295
|
|
-$ gradle test
|
|
296
|
|
-:test
|
|
297
|
|
-
|
|
298
|
|
-HelloWorldTest > helloAnotherSampleName SKIPPED
|
|
299
|
|
-
|
|
300
|
|
-HelloWorldTest > helloNoName FAILED
|
|
301
|
|
- org.junit.ComparisonFailure: expected:<Hello, [World]!> but was:<Hello, []!>
|
|
302
|
|
- at org.junit.Assert.assertEquals(Assert.java:125)
|
|
303
|
|
- at org.junit.Assert.assertEquals(Assert.java:147)
|
|
304
|
|
- at HelloWorldTest.helloNoName(HelloWorldTest.java:10)
|
|
305
|
|
-
|
|
306
|
|
-HelloWorldTest > helloSampleName PASSED
|
|
307
|
|
-
|
|
308
|
|
-3 tests completed, 1 failed, 1 skipped
|
|
309
|
|
-```
|
|
310
|
|
-
|
|
311
|
|
-Wait... didn't we just fix the test? Why is it failing? Take a closer look...
|
|
312
|
|
-
|
|
313
|
|
-In fact, `helloSampleName()` *is* passing. It's just that at the same time,
|
|
314
|
|
-we just inadvertently broke that first test: `helloNoName()`.
|
|
315
|
|
-
|
|
316
|
|
-This is one tiny example of the benefit of maintaining a test suite: if we
|
|
317
|
|
-use them to drive out our code, the second we break the program the tests
|
|
318
|
|
-say so. Since we saw them passing just *before* our latest change,
|
|
319
|
|
-whatever we *just* did most likely cause that regression.
|
|
320
|
|
-
|
|
321
|
|
-Our latest change was making the greeting dependent on the name given. Our
|
|
322
|
|
-first test expects that if either a blank string or null are given as the
|
|
323
|
|
-name, then "`World`" should be substituted in. Let's implement that.
|
|
324
|
|
-
|
|
325
|
|
-`src/main/java/HelloWorld.java`:
|
|
326
|
|
-```java
|
|
327
|
|
-public class HelloWorld {
|
|
328
|
|
- public static String hello(String name) {
|
|
329
|
|
- if(name == null || "".equals(name)) {
|
|
330
|
|
- name = "World";
|
|
331
|
|
- }
|
|
332
|
|
- return "Hello, " + name + "!";
|
|
333
|
|
- }
|
|
334
|
|
-}
|
|
335
|
|
-```
|
|
336
|
|
-
|
|
337
|
|
-... and re-run the tests ...
|
|
338
|
|
-
|
|
339
|
|
-```
|
|
340
|
|
-$ gradle test
|
|
341
|
|
-...
|
|
342
|
|
-:test
|
|
343
|
|
-
|
|
344
|
|
-HelloWorldTest > helloNoName PASSED
|
|
345
|
|
-
|
|
346
|
|
-HelloWorldTest > helloSampleName PASSED
|
|
347
|
|
-
|
|
348
|
|
-HelloWorldTest > helloAnotherSampleName SKIPPED
|
|
349
|
|
-
|
|
350
|
|
-BUILD SUCCESSFUL
|
|
351
|
|
-
|
|
352
|
|
-Total time: 4.804 secs
|
|
353
|
|
-```
|
|
354
|
|
-
|
|
355
|
|
-Excellent! We're now (at least) two-thirds the way done. Just one more
|
|
356
|
|
-test to go...
|
|
357
|
|
-
|
|
358
|
|
-
|
|
359
|
|
-
|
|
360
|
|
-## Enabling the last test
|
|
361
|
|
-
|
|
362
|
|
-(Re)open `src/test/java/HelloWorldTest.java` and find the last test:
|
|
363
|
|
-
|
|
364
|
|
-```java
|
|
365
|
|
-...
|
|
366
|
|
-@Test
|
|
367
|
|
-@Ignore
|
|
368
|
|
-public void helloAnotherSampleName() {
|
|
369
|
|
- assertEquals("Hello, Bob!", HelloWorld.hello("Bob"));
|
|
370
|
|
-}
|
|
371
|
|
-...
|
|
372
|
|
-```
|
|
373
|
|
-
|
|
374
|
|
-... and remove it's `@Ignore` to enable it ...
|
|
375
|
|
-
|
|
376
|
|
-```java
|
|
377
|
|
-...
|
|
378
|
|
-@Test
|
|
379
|
|
-public void helloAnotherSampleName() {
|
|
380
|
|
- assertEquals("Hello, Bob!", HelloWorld.hello("Bob"));
|
|
381
|
|
-}
|
|
382
|
|
-...
|
|
383
|
|
-```
|
|
384
|
|
-
|
|
385
|
|
-... and re-run the tests ...
|
|
386
|
|
-
|
|
387
|
|
-```
|
|
388
|
|
-$ gradle test
|
|
389
|
|
-:compileJava UP-TO-DATE
|
|
390
|
|
-:processResources UP-TO-DATE
|
|
391
|
|
-:classes UP-TO-DATE
|
|
392
|
|
-:compileTestJava
|
|
393
|
|
-:processTestResources UP-TO-DATE
|
|
394
|
|
-:testClasses
|
|
395
|
|
-:test
|
|
396
|
|
-
|
|
397
|
|
-HelloWorldTest > helloNoName PASSED
|
|
398
|
|
-
|
|
399
|
|
-HelloWorldTest > helloSampleName PASSED
|
|
400
|
|
-
|
|
401
|
|
-HelloWorldTest > helloAnotherSampleName PASSED
|
|
402
|
|
-
|
|
403
|
|
-BUILD SUCCESSFUL
|
|
404
|
|
-
|
|
405
|
|
-Total time: 6.953 secs
|
|
406
|
|
-```
|
|
407
|
|
-
|
|
408
|
|
-Oh, hello! Turns out, the solution we put into place didn't just apply for
|
|
409
|
|
-"`Alice`" but "`Bob`" equally well. In this case, the test succeeded with
|
|
410
|
|
-no additional code on our part.
|
|
411
|
|
-
|
|
412
|
|
-
|
|
413
|
|
-
|
|
414
|
|
-## Refactoring
|
|
415
|
|
-
|
|
416
|
|
-Now that you've got all the tests passing, you might consider whether
|
|
417
|
|
-the code is in the most readable/maintainable/efficient shape. What makes
|
|
418
|
|
-for "good" design of software is a big topic. The pursuit of it underlies
|
|
419
|
|
-much of what makes up the more valuable conversations on Exercism.
|
|
420
|
|
-
|
|
421
|
|
-For now, let's just take a quick review of our solution and see if there's
|
|
422
|
|
-any part of it we'd like to refactor. Refactoring is changing the the way
|
|
423
|
|
-a bit of code reads without changing what it does.
|
|
424
|
|
-
|
|
425
|
|
-Right now, the details of detecting whether the caller of `hello()` has
|
|
426
|
|
-given a name or not (i.e. `name` is either `null` or an empty string) is
|
|
427
|
|
-sitting right next to the core responsibility of the method: to produce a
|
|
428
|
|
-personalized greeting.
|
|
429
|
|
-
|
|
430
|
|
-```java
|
|
431
|
|
-public class HelloWorld {
|
|
432
|
|
- public static String hello(String name) {
|
|
433
|
|
- if(name == null || "".equals(name)) {
|
|
434
|
|
- name = "World";
|
|
435
|
|
- }
|
|
436
|
|
- return "Hello, " + name + "!";
|
|
437
|
|
- }
|
|
438
|
|
-}
|
|
439
|
|
-```
|
|
440
|
|
-
|
|
441
|
|
-How would things read if we extracted those details into a separate method
|
|
442
|
|
-and at the same time, replaced the `if` with a ternary expression?
|
|
443
|
|
-
|
|
444
|
|
-```java
|
|
445
|
|
-public class HelloWorld {
|
|
446
|
|
-
|
|
447
|
|
- public static String hello(String name) {
|
|
448
|
|
- String whom = isBlank(name) ? "World" : name;
|
|
449
|
|
- return "Hello, " + whom + "!";
|
|
450
|
|
- }
|
|
451
|
|
-
|
|
452
|
|
- private static boolean isBlank(String string) {
|
|
453
|
|
- return string == null || "".equals(string);
|
|
454
|
|
- }
|
|
455
|
|
-}
|
|
456
|
|
-```
|
|
457
|
|
-
|
|
458
|
|
-By extracting that logic into the `isBlank()` method, we've added a little
|
|
459
|
|
-abstraction to our program -- it's not as literal as it was before. Yet,
|
|
460
|
|
-it allows us to defer *needing* to understand *how* "blankness" is
|
|
461
|
|
-detected. If we can assume that `isBlank()` just works, we don't have to
|
|
462
|
|
-downshift in our head to those details. Instead, we can remain at the same
|
|
463
|
|
-level of thinking: to whom are we greeting?
|
|
|
10
|
+The following instructions work equally well on Windows, Mac OS X and Linux.
|
|
464
|
11
|
|
|
465
|
|
-The ternary operator allowed us to express that choice in a more compact
|
|
466
|
|
-form. Less to read without losing the intent.
|
|
|
12
|
+## Solve "Hello World"
|
|
467
|
13
|
|
|
468
|
|
-Finally, we introduced another variable: `whom`. Doing so gives a name to
|
|
469
|
|
-the output of the ternary expression. We certainly could have continued
|
|
470
|
|
-to reuse `name`, but by introducing a second `String` to hold the
|
|
471
|
|
-calculated value this keeps crisp the two ideas: `name` is what's given
|
|
472
|
|
-and `whom` is what's been determined.
|
|
|
14
|
+Try writing a solution that passes one test at a time, running Gradle each time:
|
|
473
|
15
|
|
|
474
|
|
-We made a bunch of changes, let's make sure we didn't break the program!
|
|
475
|
16
|
|
|
476
|
17
|
```
|
|
477
|
18
|
$ gradle test
|
|
478
|
|
-...
|
|
479
|
|
-HelloWorldTest > helloNoName PASSED
|
|
480
|
|
-
|
|
481
|
|
-HelloWorldTest > helloSampleName PASSED
|
|
482
|
|
-
|
|
483
|
|
-HelloWorldTest > helloAnotherSampleName PASSED
|
|
484
|
|
-...
|
|
485
|
19
|
```
|
|
486
|
20
|
|
|
487
|
|
-This illustrates another benefit of writing tests: you can make significant
|
|
488
|
|
-changes to the structure of the program and very quickly restore your
|
|
489
|
|
-confidence that the program still works. These tests are a far cry from a
|
|
490
|
|
-"proof" of correctness, but well-written tests do a much better job of
|
|
491
|
|
-(very quickly) giving us evidence that it is. Without them, we manually
|
|
492
|
|
-run the program with different inputs and/or inspecting the code
|
|
493
|
|
-line-by-line -- time-consuming and error prone.
|
|
494
|
|
-
|
|
|
21
|
+## Iterate through the tests
|
|
495
|
22
|
|
|
|
23
|
+After your first test passes, remove the `@Ignore` from the next test, and ierate on your solution,
|
|
|
24
|
+testing after each change.
|
|
496
|
25
|
|
|
497
|
|
-# Submitting your first iteration
|
|
|
26
|
+## All the tests pass? Submit your solution!
|
|
498
|
27
|
|
|
499
|
28
|
With a working solution that we've reviewed, we're ready to submit it to
|
|
500
|
29
|
exercism.io.
|
|
|
@@ -503,72 +32,17 @@ exercism.io.
|
|
503
|
32
|
$ exercism submit src/main/java/HelloWorld.java
|
|
504
|
33
|
```
|
|
505
|
34
|
|
|
506
|
|
-
|
|
507
|
|
-
|
|
508
|
|
-# Next Steps
|
|
|
35
|
+## Next Steps
|
|
509
|
36
|
|
|
510
|
37
|
From here, there are a number of paths you can take.
|
|
511
|
38
|
|
|
|
39
|
+1. Move on to the next exercise
|
|
|
40
|
+2. Review (and comment on) others' submissions to this exercise
|
|
|
41
|
+3. Submit another iteration
|
|
|
42
|
+4. Contribute to Exercism
|
|
512
|
43
|
|
|
513
|
|
-## Move on to the next exercise
|
|
514
|
|
-
|
|
515
|
|
-There are many more exercises you can practice with. Grab the next one!
|
|
516
|
|
-
|
|
517
|
|
-```
|
|
518
|
|
-$ exercism fetch java
|
|
519
|
|
-```
|
|
520
|
|
-
|
|
521
|
|
-
|
|
522
|
|
-## Review (and comment on) others' submissions to this exercise
|
|
523
|
|
-
|
|
524
|
|
-The heart of Exercism are the conversations about coding
|
|
525
|
|
-practices. It's definitely fun to practice, but engaging with others
|
|
526
|
|
-both in their attempts and your own is how you get feedback. That feedback
|
|
527
|
|
-can help point out what you're doing well and where you might need to
|
|
528
|
|
-improve.
|
|
529
|
|
-
|
|
530
|
|
-Some submissions will be nearly identical to yours; others will be
|
|
531
|
|
-completely different. Seeing both kinds can be instructive and interesting.
|
|
532
|
|
-
|
|
533
|
|
-Note that you can only view submissions of others for exercises you have
|
|
534
|
|
-completed yourself. This enriches the experience of reading others' code
|
|
535
|
|
-because you'll have your own experience of trying to solve the problem.
|
|
536
|
|
-
|
|
537
|
|
-Here's an up-to-date list of submissions on the Java track:
|
|
538
|
|
-
|
|
539
|
|
-http://exercism.io/tracks/java/exercises
|
|
540
|
|
-
|
|
541
|
|
-
|
|
542
|
|
-
|
|
543
|
|
-## Submit another iteration
|
|
544
|
|
-
|
|
545
|
|
-You are also encouraged to consider additional "requirements" on a given
|
|
546
|
|
-exercise.
|
|
547
|
|
-
|
|
548
|
|
-For example, you could add a test or two that requires that the greeting
|
|
549
|
|
-use the capitalized form on the person's name, regardless of the case they
|
|
550
|
|
-used.
|
|
551
|
|
-
|
|
552
|
|
-In that situation, you'd write a test to set-up that new expectation and
|
|
553
|
|
-then implement that in the code (the same process we just went through
|
|
554
|
|
-together, above).
|
|
555
|
|
-
|
|
556
|
|
-
|
|
557
|
|
-
|
|
558
|
|
-## Contribute to Exercism
|
|
559
|
|
-
|
|
560
|
|
-The entire of Exercism is Open Source and is the labor of love for over
|
|
561
|
|
-100 maintainers and many more contributors.
|
|
562
|
|
-
|
|
563
|
|
-A starting point to jumping in can be found here:
|
|
564
|
|
-
|
|
565
|
|
-https://github.com/exercism/x-common/blob/master/CONTRIBUTING.md
|
|
566
|
|
-
|
|
567
|
|
-
|
|
568
|
|
-----
|
|
569
|
44
|
|
|
570
|
|
-Regardless of what you decide to do next, we sincerely hope you learn
|
|
571
|
|
-and enjoy being part of this community. If at any time you need assistance
|
|
|
45
|
+We sincerely hope you learn and enjoy being part of this community. If at any time you need assistance
|
|
572
|
46
|
do not hesitate to ask for help:
|
|
573
|
47
|
|
|
574
|
48
|
http://exercism.io/languages/java/help
|