
library(testthat)

source("user_code.R")
test_that("returns correct counts for each month present in input", {
  dates <- c("2022-01-12", "2022-01-25", "2022-02-03", "2022-02-14", "2022-03-01")
  result <- count_month_entries(dates)
  expect_true(is.table(result), "Result should be a table")
  expect_equal(as.integer(result["January"]), 2, info = "Should count 2 entries for January")
  expect_equal(as.integer(result["February"]), 2, info = "Should count 2 entries for February")
  expect_equal(as.integer(result["March"]), 1, info = "Should count 1 entry for March")
})

test_that("correctly parses date strings in YYYY-MM-DD format", {
  dates <- c("2021-12-31", "2022-01-01", "2022-01-15", "2022-02-28")
  result <- count_month_entries(dates)
  expect_true("December" %in% names(result), "Should include December in result")
  expect_true("January" %in% names(result), "Should include January in result")
  expect_true("February" %in% names(result), "Should include February in result")
})

test_that("handles months with multiple entries", {
  dates <- c("2022-05-01", "2022-05-15", "2022-05-20")
  result <- count_month_entries(dates)
  expect_equal(as.integer(result["May"]), 3, info = "Should count 3 entries for May")
  expect_equal(length(result), 1, info = "Should only be one month in result")
})

test_that("handles all dates in the same month", {
  dates <- c("2022-07-01", "2022-07-10", "2022-07-15")
  result <- count_month_entries(dates)
  expect_equal(as.integer(result["July"]), 3, info = "Should count 3 entries for July")
  expect_equal(length(result), 1, info = "Should only be one month in result")
})

test_that("handles each date in a different month", {
  dates <- c("2022-08-01", "2022-09-10", "2022-10-15")
  result <- count_month_entries(dates)
  expect_equal(as.integer(result["August"]), 1, info = "Should count 1 entry for August")
  expect_equal(as.integer(result["September"]), 1, info = "Should count 1 entry for September")
  expect_equal(as.integer(result["October"]), 1, info = "Should count 1 entry for October")
  expect_equal(length(result), 3, info = "Should be three months in result")
})

test_main.R

Master the essential R data structures used in exploratory data analysis (EDA), focusing on practical applications and hands-on challenges. This course is designed for learners already familiar with R syntax, core data structures, and data cleaning/wrangling techniques.

Explore the essential R data structures that power effective exploratory data analysis, with a focus on practical usage and hands-on challenges.

Challenge: Dates and Times

Solution