Merge bitcoin/bitcoin#31415: test: fix TestShell initialization and reset()

303f8cc test: fix TestShell initialization and reset() (Brandon Odiwuor)

Pull request description:

  Fixes TestShell initialization issues caused by resolving symlinks and looking for config.ini in the source path instead of the build path after migration to CMake (see bitcoin/bitcoin#31131 (comment))

  https://github.com/bitcoin/bitcoin/blob/ebe4cac38bf6c510b00b8e080acab079c54016d6/test/functional/test_framework/test_shell.py#L77
  also fixes bitcoin/bitcoin#31131

  **How to test:**
  ```
  $ python3
  >>> import sys
  >>> sys.path.insert(0, "./path/to/bitcoin/build/test/functional")
  >>> from test_framework.test_shell import TestShell
  >>> TestShell().setup(num_nodes=2, setup_clean_chain=True)
  >>> TestShell().shutdown()
  >>> TestShell.reset()
  ```

ACKs for top commit:
  pinheadmz:
    ACK 303f8cc
  theStack:
    Tested ACK 303f8cc
  pablomartin4btc:
    re-ACK 303f8cc

Tree-SHA512: 25396eb2f7e4bf14426399b1eb3d2c988903ab1f3d38a58f1044b67dd7200c11c01686578fb49b0f2943864166c5c9ccbf122b45202a1e723bf3dbf0c90020fa

Author: fanquake

test/functional/test-shell.md

@@ -24,13 +24,16 @@ user inputs. Such environments include the Python3 command line interpreter or
 
 ## 2. Importing `TestShell` from the Bitcoin Core repository
 
-We can import the `TestShell` by adding the path of the Bitcoin Core
+We can import the `TestShell` by adding the path of the configured Bitcoin Core
 `test_framework` module to the beginning of the PATH variable, and then
-importing the `TestShell` class from the `test_shell` sub-package.
+importing the `TestShell` class from the `test_shell` sub-package. Since
+the build system creates a copy of the `test_framework` module into a new `build/`
+directory along with the required configuration file, the path to the build copy
+must be used.
 
 ```
 >>> import sys
->>> sys.path.insert(0, "/path/to/bitcoin/test/functional")
+>>> sys.path.insert(0, "/path/to/bitcoin/build/test/functional")
 >>> from test_framework.test_shell import TestShell
 ```
 
@@ -155,7 +158,7 @@ To prevent the logs from being removed after a shutdown, simply set the
 The following utility consolidates logs from the bitcoind nodes and the
 underlying `BitcoinTestFramework`:
 
-* `/path/to/bitcoin/test/functional/combine_logs.py
+* `/path/to/bitcoin/build/test/functional/combine_logs.py
   '/path/to/bitcoin_func_test_XXXXXXX'`
 
 ## 6. Custom `TestShell` parameters
@@ -170,9 +173,9 @@ can be called after the TestShell is shut down.
 | Test parameter key | Default Value | Description |
 |---|---|---|
 | `bind_to_localhost_only` | `True` | Binds bitcoind P2P services to `127.0.0.1` if set to `True`.|
-| `cachedir` | `"/path/to/bitcoin/test/cache"` | Sets the bitcoind datadir directory. |
+| `cachedir` | `"/path/to/bitcoin/build/test/cache"` | Sets the bitcoind datadir directory. |
 | `chain`  | `"regtest"` | Sets the chain-type for the underlying test bitcoind processes. |
-| `configfile` | `"/path/to/bitcoin/test/config.ini"` | Sets the location of the test framework config file. |
+| `configfile` | `"/path/to/bitcoin/build/test/config.ini"` | Sets the location of the test framework config file. |
 | `coveragedir` | `None` | Records bitcoind RPC test coverage into this directory if set. |
 | `loglevel` | `INFO` | Logs events at this level and higher. Can be set to `DEBUG`, `INFO`, `WARNING`, `ERROR` or `CRITICAL`. |
 | `nocleanup` | `False` | Cleans up temporary test directory if set to `True` during `shutdown`. |

test/functional/test_framework/test_shell.py

@@ -61,7 +61,8 @@ def reset(self):
                 print("Shutdown TestShell before resetting!")
             else:
                 self.num_nodes = None
-                super().__init__()
+                dummy_testshell_file = pathlib.Path(__file__).absolute().parent.parent / "testshell_dummy.py"
+                super().__init__(dummy_testshell_file)
 
     instance = None
 
@@ -74,8 +75,8 @@ def __new__(cls):
             # cache. Since TestShell is meant for interactive use, there is no concrete
             # test; passing a dummy name is fine though, as only the containing directory
             # is relevant for successful initialization.
-            tests_directory = pathlib.Path(__file__).resolve().parent.parent
-            TestShell.instance = TestShell.__TestShell(tests_directory / "testshell_dummy.py")
+            dummy_testshell_file = pathlib.Path(__file__).absolute().parent.parent / "testshell_dummy.py"
+            TestShell.instance = TestShell.__TestShell(dummy_testshell_file)
             TestShell.instance.running = False
         return TestShell.instance