Minor changes to Module 3

Author: ecomodeller

03_testing.qmd

@@ -25,15 +25,10 @@ Automatic testing verifies code is still working.
 
 ## Testing workflow
 
-```{mermaid}
-flowchart TD
-    A[Prepare inputs]
-    B[Describe expected output]
-    C[Obtain actual output]
-    D[Compare actual and\n expected output]
-
-    A --> B --> C --> D
-```
+1. Prepare inputs
+2. Describe expected output
+3. Obtain actual output
+4. Compare actual and expected output
 
 
 ## Unit testing
@@ -87,28 +82,16 @@ flowchart TD
 
 ## Example
 
-1. get a timeseries of water levels
-2. find the maxiumum water level each year
-3. create a summary report for the subset of data
-
----
-
-1. get a timeseries of water levels
-
-```python
-def test_get_water_level_includes_start_and_end():
-    wl = get_water_level(time="2019-01-01", location="Aarhus")
-    
-    assert len(wl) == 25
-```
+1. find the maximum water level each year
+2. create a summary report for the subset of data
 
 ---
 
-2. find the maxiumum water level each year
+1. find the maximum water level each year
 
 ```python
 def test_get_max_water_level():
-    ts = TimeSeries([1.0, .., 3.0], start = "2019-01-01")
+    ts = TimeSeries([1.0, 2.0, ..., 3.0], start = "2019-01-01")
     max_wls = get_max_water_level(ts, freq="Y")
 
     assert len(max_wls) == 1
@@ -117,15 +100,15 @@ def test_get_max_water_level():
 
 ---
 
-3. create a summary report for the subset of data
+2. create a summary report for the subset of data
 
 ```python
 def test_summary_report():
     max_wls = [1.0, 2.0, 3.0]
-    report = summary_report(max_wls)
+    report = summary_report(max_wls, station="Station A")
 
-    assert report.title == "Summary report"
-    assert report.text == "The maximum water level in 2021 was 3.0 m"
+    assert report.title == "Summary report - Station A"
+    assert report.text == "The maximum water level during the year was 3.0 m"
 ```
 
 ## Integration testing
@@ -142,6 +125,25 @@ def test_integration():
 ```
 
 
+## Regression testing
+
+::: {.incremental}
+
+* Not a distinct test type, but a process
+
+* A regression = when code changes break previously working behavior
+
+* Regression testing = rerunning your existing test suite after each change
+
+* Test suite grows over time:
+
+    - Unit/integration tests
+
+    - Tests added for fixed bugs
+
+* Goal: ensure new changes don’t reintroduce old bugs or unexpected behavior
+:::
+
 ## Testing in VS Code
 
 ![](images/vs_code_test.png)
@@ -165,7 +167,7 @@ def test_integration():
 ```python
 @pytest.fixture
 def water_level():
-    return TimeSeries([1.0, .., 3.0], start = "2019-01-01")
+    return TimeSeries([1.0, ..., 3.0], start = "2019-01-01")
 
 def test_get_max_water_level(water_level):
     max_wls = get_max_water_level(water_level, freq="Y")
@@ -180,7 +182,7 @@ def test_get_max_water_level(water_level):
 ::: {.incremental}
 
 * A measure of how much of your code is tested
-* A good test suite should cover all the code
+* Aim for high coverage, but focus on meaningful tests
 * Install `pytest-cov`
 * Run tests with coverage report
     - `pytest --cov=myproj`
@@ -225,7 +227,7 @@ TOTAL                  353     20    94%
 
 ::: 
 
-## Tests act as specification
+## Tests document expected behavior
 
 ```python
 def test_operable_period_can_be_missing():
@@ -308,7 +310,7 @@ Readability counts.
     + `KeyError`
     + `ValueError`
     + `FileNotFoundError`
-* You can also create your own custom exceptions, e.g. `ModelInitialistionError`, `MissingLicenseError`?
+* You can also create your own custom exceptions, e.g. `ModelInitError`, `MissingLicenseError`?
 
 :::
 
@@ -358,9 +360,9 @@ The same can be done with warnings.
 
 ## Linting
 
-A way to check your code for common errors and style issues.
+A quick way to check your code for common errors and style issues.
 
-[`ruff`](https://docs.astral.sh/ruff/) is a new tool for linting Python code.
+[`ruff`](https://docs.astral.sh/ruff/) is a recent tool for linting Python code.
 
 * syntax errors
 * unused imports
@@ -409,7 +411,7 @@ Found 3 errors.
 * Formatting code for readability and maintainability is essential.
 * `ruff` can be used for code formatting (in addition to linting).
 * `ruff` is a faster replacement of `black`, a previously commonly used code formatter.
-* It enforces its own rules for formatting, which are only minorly configurable.
+* It enforces its own rules for formatting, with limited configurability.
 * Having a unified style makes code changes easier to understand and collaborate on.
 
 :::
@@ -461,7 +463,7 @@ Visual Studio Code can be configured to run `ruff format` automatically when sav
 ```python
 import numpy as np
 
-def top_neighbors(points, radius="0.1"):
+def top_neighbors(points, radius=0.1):
     """Don't use this function, it's only purpose is to be profiled."""
     n = len(points)
     idx = np.array([int(x) for x in str.split("0 "* n)])