Refactor ob-shell/bash-uses-assoc-arrays

* testing/lisp/test-ob-shell.el (ob-shell/bash-uses-assoc-arrays):
Split test cases into separate tests,
`test-ob-shell/bash-uses-assoc-arrays' and
`test-ob-shell/bash-uses-assoc-arrays-with-lists'.  Rename prefix from
"ob-shell" to "test-ob-shell".
(ob-shell/bash-uses-assoc-arrays): Move comments from
testing/examples/ob-shell-test.org to docstrings.
(ob-shell/bash-uses-assoc-arrays): Remove dependency on
testing/examples/ob-shell-test.org.

testing/lisp/test-ob-shell.el

@@ -118,21 +118,44 @@ echo ${table}
      (equal "bread 2 kg spaghetti 20 cm milk 50 dl"
             (org-trim (org-babel-execute-src-block))))))
 
-(ert-deftest ob-shell/bash-uses-assoc-arrays ()
-  "Bash associative arrays"
-  (should
-   (equal "two"
-	  (org-test-at-id
-	   "bec1a5b0-4619-4450-a8c0-2a746b44bf8d"
-	   (org-babel-next-src-block 2)
-	   (org-trim (org-babel-execute-src-block)))))
-  ;; Bash associative arrays as strings for the row.
-  (should
-   (equal "20 cm"
-	  (org-test-at-id
-	   "82320a48-3409-49d7-85c9-5de1c6d3ff87"
-	   (org-babel-next-src-block 2)
-	   (org-trim (org-babel-execute-src-block))))))
+(ert-deftest test-ob-shell/bash-uses-assoc-arrays ()
+  "Bash shell: support for associative arrays
+
+Bash will see a table that contains the first column as the
+'index' of the associative array, and the second column as the
+value. "
+  (org-test-with-temp-text
+      "#+NAME: sample_mapping_table
+| first  | one   |
+| second | two   |
+| third  | three |
+
+#+begin_src bash :exports :results output results :var table=sample_mapping_table
+echo ${table[second]}
+<point>
+#+end_src "
+    (should
+     (equal "two"
+            (org-trim (org-babel-execute-src-block))))))
+
+(ert-deftest test-ob-shell/bash-uses-assoc-arrays-with-lists ()
+  "Bash shell: support for associative arrays with lists
+
+Bash will see an associative array that contains each row as a single
+string. Bash cannot handle lists in associative arrays."
+  (org-test-with-temp-text
+      "#+NAME: sample_big_table
+| bread     |  2 | kg |
+| spaghetti | 20 | cm |
+| milk      | 50 | dl |
+
+#+begin_src bash :exports results :results output :var table=sample_big_table
+echo ${table[spaghetti]}
+<point>
+#+end_src"
+    (should
+     (equal "20 cm"
+            (org-trim (org-babel-execute-src-block))))))
 
 (ert-deftest ob-shell/simple-list ()
   "Test list variables in shell."