Script testing strategies in Bash Scripting - Step-by-Step Execution

Concept Flow - Script testing strategies

Write script

↓

Add test cases

↓

Run script with test inputs

↓

Check outputs

↓

Compare with expected results

↓

Use script

↓

Repeat tests

This flow shows writing a script, adding tests, running them, checking outputs, and fixing errors until tests pass.

Execution Sample

Bash Scripting

#!/bin/bash
# Simple test for greeting function
say_hello() {
  echo "Hello, $1!"
}
result=$(say_hello Alice)
echo "$result"

This script defines a function that greets a name and tests it by calling with 'Alice' and printing the result.

Execution Table

Step	Action	Input	Output	Result
1	Define function say_hello	-	-	Function ready
2	Call say_hello with 'Alice'	Alice	Hello, Alice!	Output captured
3	Print result	-	Hello, Alice!	Output matches expected
4	Compare output to expected	Hello, Alice!	Hello, Alice!	Test Pass

💡 Test passes because output matches expected greeting

Variable Tracker

Variable	Start	After Step 2	After Step 3	Final
result	empty	Hello, Alice!	Hello, Alice!	Hello, Alice!

Key Moments - 3 Insights

Why do we compare the script output to expected results?

Comparing output to expected results (see execution_table step 4) confirms the script works correctly for given inputs.

What if the output does not match expected?

If output differs (fail branch in concept_flow), we fix the script and rerun tests until outputs match.

Why add test cases before running the script?

Adding test cases early (concept_flow step 2) helps catch errors quickly and ensures script behaves as intended.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of 'result' after step 2?

A Hello, Alice!

B empty

C Hello, World!

D Error

💡 Hint

Check variable_tracker row for 'result' after Step 2

At which step does the script output get compared to the expected result?

A Step 1

B Step 3

C Step 4

D Step 2

💡 Hint

See execution_table 'Compare output to expected' action

If the output was 'Hello, Bob!' instead of 'Hello, Alice!', what would happen next?

A Test passes

B Script is fixed and tests rerun

C Script is used as is

D Test is skipped

💡 Hint

Refer to concept_flow where Fail leads to fixing script and repeating tests

Concept Snapshot

Script Testing Strategies:
1. Write your script.
2. Add test cases with expected outputs.
3. Run script with test inputs.
4. Check actual output.
5. Compare output to expected.
6. Fix script if tests fail and repeat.

Full Transcript

Script testing strategies involve writing a script and then creating test cases to check if it works correctly. You run the script with test inputs and capture the output. Then you compare this output to what you expect. If they match, the test passes and you can use the script. If not, you fix the script and test again. This cycle continues until all tests pass, ensuring your script works as intended.