Added unit tests for compile_grammar and improve coverage for read_le…

…xicon functions

R/compile_grammar.R

@@ -15,7 +15,7 @@
 #' # A more complete demo:
 #' # 1. Read a lexicon and group lines using zoo:na.locf0()
 #' lexicon_df <-
-#' system.file("extdata", "error-french.txt", package = "tidylex") %>%
+#'     system.file("extdata", "error-french.txt", package = "tidylex") %>%
 #'     read_lexicon(regex = "\\\\([a-z]+)\\s(.*)", into  = c("code", "value")) %>%
 #'     mutate(lx_line = ifelse(code == "lx", line, NA) %>% zoo::na.locf0())
 #'

inst/extdata/basic-nearley-grammar.ne

@@ -0,0 +1,9 @@
+# Default basic grammar from Nearley playground:
+# https://omrelli.ug/nearley-playground/
+MAIN -> SENTENCE "."
+SENTENCE -> SUB _ VERB _ MOD
+SUB -> "My dog" | "Charles" | "A typical Reddit user"
+VERB -> "sleeps" | "thinks" | "cries" | "tweets" | "believes in ponies"
+MOD -> "with" _ OBJ | "while thinking about" _ OBJ | "better than" _ OBJ _ "can" | "agressively" | "but" _ SENTENCE
+OBJ -> "a hammer" | "nobody" | "snakes"
+_ -> " "

tests/testthat/test-compile_grammar.R

@@ -0,0 +1,77 @@
+context("compile_grammar")
+
+basic_grammar <-
+'# Default basic grammar from Nearley playground:
+# https://omrelli.ug/nearley-playground/
+MAIN -> SENTENCE "."
+SENTENCE -> SUB _ VERB _ MOD
+SUB -> "My dog" | "Charles" | "A typical Reddit user"
+VERB -> "sleeps" | "thinks" | "cries" | "tweets" | "believes in ponies"
+MOD -> "with" _ OBJ | "while thinking about" _ OBJ | "better than" _ OBJ _ "can" | "agressively" | "but" _ SENTENCE
+OBJ -> "a hammer" | "nobody" | "snakes"
+_ -> " "
+'
+
+test_that("non-string input values rejected by function", {
+    expect_error(compile_grammar(TRUE))
+    expect_error(compile_grammar(154))
+    expect_error(compile_grammar(mtcars))
+})
+
+test_that("Invalid Nearley grammar throws syntax error", {
+    expect_error(compile_grammar("MAIN <- SENTENCE"))
+})
+
+test_that("Nearley .ne grammar files are read in properly", {
+
+    # Can't expect identical since bytecode will be equal but
+    # will be in different environments
+    expect_equal(
+        compile_grammar(basic_grammar),
+        compile_grammar(system.file("extdata", "basic-nearley-grammar.ne", package = "tidylex"))
+    )
+
+})
+
+test_that("tests against basic nearley grammar return as expected", {
+
+    expect_identical(
+        # Correct parse
+        compile_grammar(basic_grammar)("Charles sleeps while thinking about snakes."),
+        list(
+            list(                       # MAIN
+                list(                       # SENTENCE
+                    "Charles",                  # SUB
+                    " ",                        # _
+                    "sleeps",                   # VERB
+                    " ",                        # _
+                    list(                       # MOD
+                        "while thinking about", #    "while thinking about"
+                        " ",                    #    _
+                        "snakes"                #    OBJ
+                    )
+                ),
+            ".")                            # "."
+        )
+    )
+
+    expect_error(
+        # Incomplete parse
+        compile_grammar(basic_grammar)("Charles sleeps while thinking about ")
+    )
+
+    expect_error(
+        # Invalid parse
+        compile_grammar(basic_grammar)("This test doesn't match :(")
+    )
+
+    # As above, but error messages returned when told not to stop script
+    expect_true(
+        "error" %in% names(compile_grammar(basic_grammar)("Charles sleeps while thinking about ", stop_on_error = FALSE))
+    )
+
+    expect_true(
+        "error" %in% names(compile_grammar(basic_grammar)("This test doesn't match :(", stop_on_error = FALSE))
+    )
+
+})

tests/testthat/test-read_lexicon.R

@@ -1,15 +1,28 @@
 context("read_lexicon")
 
+check_df  <- tibble(
+    line  = 1:5,
+    data  = c("\\lx bonjour", "\\de hello", "", "\\lx au revoir", "\\de goodbye"),
+    code  = c("lx", "de", NA, "lx", "de"),
+    value = c("bonjour", "hello", NA, "au revoir", "goodbye")
+)
+
+test_file <- system.file("extdata", "mini-french.txt", package = "tidylex")
+
 test_that("can read mini French lexicon", {
-    check_df  <- tibble(
-        line = 1:5,
-        data = c("\\lx bonjour", "\\de hello", "", "\\lx au revoir", "\\de goodbye")
-    )
-
-    test_file <- system.file("extdata", "mini-french.txt", package = "tidylex")
-
+
     expect_identical(
         read_lexicon(file = test_file),
+        check_df[, 1:2]
+    )
+
+})
+
+test_that("codes and values are extracted correctly from mini French lexicon", {
+
+    expect_identical(
+        read_lexicon(file = test_file, regex = "\\\\([a-z]+)\\s(.*)", into = c("code", "value")),
         check_df
     )
+
 })