feat: add exercise templates for 27 Go programming concepts

[zhravan]

Summary by CodeRabbit

• New Features

  • Expanded the exercise catalog with 14 new Go topics, including closures, recursion, range over built-ins and iterators, pointers, strings/runes, structs, methods, interfaces, enums, struct embedding, generics, errors, and custom errors. Each includes hints and starter templates.

• Tests

  • Added comprehensive unit tests for all new exercises to validate expected behaviors and edge cases.

• Chores

  • Updated dependencies to include additional testing utilities and maintainers’ tooling, improving reliability of the development and test environment.

[coderabbitai]

Caution

Review failed

The pull request is closed.

Walkthrough

Adds 14 new Go exercises (templates and tests) covering closures, recursion, range, pointers, strings/runes, structs, methods, interfaces, enums, struct embedding, generics, iterators, and errors. Updates catalog to include these exercises. Extends go.mod with additional indirect dependencies (testify, difflib, spew) via a require block.

Changes

Cohort / File(s)	Summary
Dependencies go.mod	Converted single indirect require to a require block; added indirect deps: github.com/davecgh/go-spew v1.1.1, github.com/pmezard/go-difflib v1.0.0, github.com/stretchr/testify v1.11.0; retained golang.org/x/sys v0.4.0 and existing deps.
Exercise catalog internal/exercises/catalog.yaml	Appended 14 exercise entries (14_closures … 27_custom_errors) with slug, title, test_regex ".*", and one hint each; no modifications to existing entries.
Closures internal/exercises/templates/14_closures/closures.go, internal/exercises/templates/14_closures/closures_test.go	Implemented closure that captures and increments state; tests verify state progression and isolation across instances.
Recursion internal/exercises/templates/15_recursion/recursion.go, internal/exercises/templates/15_recursion/recursion_test.go	Added recursive factorial with base case; tests cover 0, 1, 5.
Range over built-ins internal/exercises/templates/16_range_built_in/*	Implemented slice sum and map entry count using range; tests validate both helpers.
Pointers internal/exercises/templates/17_pointers/*	Function modifies value via pointer and returns same pointer; test checks value and identity.
Strings and runes internal/exercises/templates/18_strings_runes/*	Added rune counting and Unicode-safe reverse; tests include ASCII and CJK cases.
Structs internal/exercises/templates/19_structs/*	Introduced Person struct and constructor; test asserts fields.
Methods internal/exercises/templates/20_methods/*	Rectangle with Area and Scale methods; tests for area and scaling behavior.
Interfaces internal/exercises/templates/21_interfaces/*	Greeter interface, Person implementation, SayHello function; tests for Greet and SayHello.
Enums (iota) internal/exercises/templates/22_enums/*	Day enum and IsWeekend function; test verifies weekend detection.
Struct embedding internal/exercises/templates/23_struct_embedding/*	Base and embedded User types with constructor; test checks embedded field access.
Generics internal/exercises/templates/24_generics/*	Generic identity and constrained sum; tests for int and float64.
Range over iterators internal/exercises/templates/25_range_iterators/*	IntIterator with Next, constructor, and IterateInts callback loop; tests use testify and validate iteration and accumulation.
Errors internal/exercises/templates/26_errors/*	divide returns error on zero divisor; processDivision prints result or error; tests check success and division-by-zero error.
Custom errors internal/exercises/templates/27_custom_errors/*	Custom MyError with Code/Message and Error method; processInput returns error for negative input; test verifies fields and success case.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  actor Client
  participant Lib as IterateInts
  participant Ctor as NewIntIterator
  participant It as IntIterator
  participant Fn as Callback fn(int)

  Client->>Lib: IterateInts(start, end, fn)
  Lib->>Ctor: NewIntIterator(start, end)
  Ctor-->>Lib: *IntIterator
  loop while current < end
    Lib->>It: Next()
    It-->>Lib: (val, ok=true)
    Lib->>Fn: fn(val)
  end
  Lib->>It: Next()
  It-->>Lib: (0, ok=false)
  Lib-->>Client: return

Loading

sequenceDiagram
  autonumber
  participant Caller as processDivision
  participant Div as divide
  Caller->>Div: divide(a, b)
  alt b == 0
    Div-->>Caller: (0, error "division by zero")
    Caller-->>Caller: print "Error: %v"
  else b != 0
    Div-->>Caller: (a/b, nil)
    Caller-->>Caller: print "Result: %d"
  end

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

I thump my paws on tidy code,
From runes to ranges, down the road.
New tests sprout like clover green,
Enums bloom in iota sheen.
Errors hop, then calmly rest—
Generics nest; I’ve checked each test.
Nose-twitch: this patch feels… addressed. 🐇✨

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📥 Commits

Reviewing files that changed from the base of the PR and between ab26fbb and 11da324.

⛔ Files ignored due to path filters (1)

• go.sum is excluded by !**/*.sum

📒 Files selected for processing (30)

• go.mod (1 hunks)
• internal/exercises/catalog.yaml (1 hunks)
• internal/exercises/templates/14_closures/closures.go (1 hunks)
• internal/exercises/templates/14_closures/closures_test.go (1 hunks)
• internal/exercises/templates/15_recursion/recursion.go (1 hunks)
• internal/exercises/templates/15_recursion/recursion_test.go (1 hunks)
• internal/exercises/templates/16_range_built_in/range_built_in.go (1 hunks)
• internal/exercises/templates/16_range_built_in/range_built_in_test.go (1 hunks)
• internal/exercises/templates/17_pointers/pointers.go (1 hunks)
• internal/exercises/templates/17_pointers/pointers_test.go (1 hunks)
• internal/exercises/templates/18_strings_runes/strings_runes.go (1 hunks)
• internal/exercises/templates/18_strings_runes/strings_runes_test.go (1 hunks)
• internal/exercises/templates/19_structs/structs.go (1 hunks)
• internal/exercises/templates/19_structs/structs_test.go (1 hunks)
• internal/exercises/templates/20_methods/methods.go (1 hunks)
• internal/exercises/templates/20_methods/methods_test.go (1 hunks)
• internal/exercises/templates/21_interfaces/interfaces.go (1 hunks)
• internal/exercises/templates/21_interfaces/interfaces_test.go (1 hunks)
• internal/exercises/templates/22_enums/enums.go (1 hunks)
• internal/exercises/templates/22_enums/enums_test.go (1 hunks)
• internal/exercises/templates/23_struct_embedding/struct_embedding.go (1 hunks)
• internal/exercises/templates/23_struct_embedding/struct_embedding_test.go (1 hunks)
• internal/exercises/templates/24_generics/generics.go (1 hunks)
• internal/exercises/templates/24_generics/generics_test.go (1 hunks)
• internal/exercises/templates/25_range_iterators/range_iterators.go (1 hunks)
• internal/exercises/templates/25_range_iterators/range_iterators_test.go (1 hunks)
• internal/exercises/templates/26_errors/errors.go (1 hunks)
• internal/exercises/templates/26_errors/errors_test.go (1 hunks)
• internal/exercises/templates/27_custom_errors/custom_errors.go (1 hunks)
• internal/exercises/templates/27_custom_errors/custom_errors_test.go (1 hunks)

✨ Finishing Touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feat/other-concepts

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[zhravan]

@coderabbitai

[coderabbitai]

Tip

For best results, initiate chat on the files or code changes.

@zhravan Hello! I'm here and ready to help. How can I assist you with this PR that adds templates for concepts? Whether you need a review, have questions, or want me to take a specific action, just let me know!

( ᵔ ᴗ ᵔ )

[zhravan]

@coderabbitai give PR title

[coderabbitai]

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🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# Get current PR title and details
gh pr view --json title,body,headRefName,files

# List the files changed in this PR
git diff --name-only HEAD~1..HEAD

# Look for template-related files or directories
fd -t f template
fd -t d template

Length of output: 394

---

🏁 Script executed:

#!/bin/bash
# Check git status to see what files are added/modified
git status

# Look at the templates directory structure and contents
ls -la internal/exercises/templates/

# Check what's in the templates directory recursively
find internal/exercises/templates/ -type f

# Get the current branch name
git branch --show-current

# Try to get PR info with the current branch
gh pr list --head $(git branch --show-current)

Length of output: 5080

---

@zhravan Based on my analysis of the PR content, I can see that this adds a comprehensive set of exercise templates for learning Go programming concepts. The templates cover 27 different topics from basic concepts like "hello world" to advanced topics like generics and custom errors.

Here's my suggested PR title:

feat: add comprehensive Go exercise templates for 27 core concepts

Alternative titles you might consider:

• feat: add exercise templates for Go learning curriculum
• feat: add structured Go programming exercise templates
• feat: add Go concept exercise templates with tests

The current PR adds templates for fundamental Go concepts including variables, functions, data structures, object-oriented features, and error handling - each with corresponding test files. This creates a solid foundation for a structured Go learning experience.

( ᵔ ᴗ ᵔ )

---

🏁 Script executed:

#!/bin/bash
# Look at a few template files to understand their structure
echo "=== Hello template ==="
cat internal/exercises/templates/01_hello/hello.go
echo -e "\n=== Hello test template ==="
cat internal/exercises/templates/01_hello/hello_test.go

echo -e "\n=== Functions template ==="
cat internal/exercises/templates/11_functions/functions.go | head -20

Length of output: 824

---

Perfect! Now I can see the complete picture. These are exercise templates where each function has a TODO comment and intentionally incorrect implementation, designed for students to fix and make the tests pass.

Here's my refined PR title suggestion:

feat: add exercise templates for 27 Go programming concepts

This title is concise and accurately describes what's being added - a comprehensive set of hands-on exercise templates that cover the core Go programming curriculum from basic concepts to advanced topics like generics and error handling.

( ᵔ ᴗ ᵔ )