library(testthat)
library(gluedown)
library(stringr)
library(glue)
library(rvest)

test_that("md_reference creates a simple <href> tag (ex. 161)", {
  # https://github.github.com/gfm/#example-161
  ref <- md_reference("foo", "/url", "title")
  lines <- md_paragraph(ref, "[foo]")
  node <- md_convert(lines) %>% find_nodes("a") %>% html_attr("href")
  expect_equal(node, "/url")
  node <- md_convert(lines) %>% find_nodes("a") %>% html_text()
  expect_equal(node, "foo")
})

test_that("md_reference may omit the title (ex. 166)", {
  # https://github.github.com/gfm/#example-166
  ref <- md_reference("foo" = "\n/url")
  lines <- md_paragraph(ref, "[foo]")
  node <- md_convert(lines) %>% find_nodes("a") %>% html_attr("href")
  expect_equal(node, "/url")
  node <- md_convert(lines) %>% find_nodes("a") %>% html_text()
  expect_equal(node, "foo")
})

test_that("md_reference may not omit a link destination (ex. 168)", {
  # https://github.github.com/gfm/#example-168
  expect_error(md_reference("foo"))
})

test_that("md_reference can use angled link destination (ex. 169)", {
  skip("This render is not supported by markdown::markdownToHTML()")
  # https://github.github.com/gfm/#example-169
  ref <- md_reference("foo" = "<>")
  lines <- md_paragraph(ref, "[foo]")
  node <- md_convert(lines) %>% find_nodes("a") %>% html_attr("href")
  expect_equal(node, "/url")
})

test_that("md_refernce alone contributes nothing (ex. 176)", {
  node <- md_reference("foo" = "/url") %>% md_convert()
  expect_nchar(node, 0)
})