From 1c3eba149704bd6c270555f6d15d762f29213ed3 Mon Sep 17 00:00:00 2001
From: chainsawriot <chainsawtiney@gmail.com>
Date: Sun, 9 Jun 2024 14:15:45 +0200
Subject: [PATCH] Fix #430 (#431)

---
 NEWS.md                          |   8 ++-
 R/import_methods.R               |   2 +-
 R/sysdata.rda                    | Bin 2322 -> 2349 bytes
 README.md                        |  93 ++++++++++++++++---------------
 data-raw/single.json             |   9 +++
 tests/testthat/test_format_csv.R |  10 ++++
 6 files changed, 74 insertions(+), 48 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index 4b3fcf7..aee7d7f 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,6 +1,12 @@
+# rio 1.1.1.999 (development)
+
+Bug fixes
+
+* Fix #430 Add back support for `.dat`
+
 # rio 1.1.1
 
-Bus fixes
+Bug fixes
 
 * Fix #425 for archive formats, the file extension of the input file is determined by the compressed file (like prior rio 1.1.0)
 
diff --git a/R/import_methods.R b/R/import_methods.R
index edc603f..66a0550 100644
--- a/R/import_methods.R
+++ b/R/import_methods.R
@@ -29,7 +29,7 @@ import_delim <- function(file, which = 1, sep = "auto", header = "auto", strings
 
 #' @export
 .import.rio_dat <- function(file, which = 1, ...) {
-    message(sprintf("Ambiguous file format ('.dat'), but attempting 'data.table::fread(\"%s\")'", file))
+    message(sprintf("Ambiguous file format ('.dat'), but attempting 'data.table::fread(\"%s\")'\n", file))
     import_delim(file = file, ...)
 }
 
diff --git a/R/sysdata.rda b/R/sysdata.rda
index c844261721a68ad5aa2b53b0e7440108ae8d6703..3007435d7b6d08ac9e9aa576621fea19273aab5a 100644
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diff --git a/README.md b/README.md
index fa4d392..149cba6 100644
--- a/README.md
+++ b/README.md
@@ -126,52 +126,53 @@ install_formats()
 
 The full list of supported formats is below:
 
-| Name                                | Extensions / “format”               | Import Package | Export Package | Type    | Note                    |
-| :---------------------------------- | :---------------------------------- | :------------- | :------------- | :------ | :---------------------- |
-| Archive files (handled by tar)      | tar / tar.gz / tgz / tar.bz2 / tbz2 | utils          | utils          | Default |                         |
-| Bzip2                               | bz2 / bzip2                         | base           | base           | Default |                         |
-| Gzip                                | gz / gzip                           | base           | base           | Default |                         |
-| Zip files                           | zip                                 | utils          | utils          | Default |                         |
-| CSVY (CSV + YAML metadata header)   | csvy                                | data.table     | data.table     | Default |                         |
-| Comma-separated data                | csv                                 | data.table     | data.table     | Default |                         |
-| Comma-separated data (European)     | csv2                                | data.table     | data.table     | Default |                         |
-| Data Interchange Format             | dif                                 | utils          |                | Default |                         |
-| Epiinfo                             | epiinfo / rec                       | foreign        |                | Default |                         |
-| Excel                               | excel / xlsx                        | readxl         | writexl        | Default |                         |
-| Excel (Legacy)                      | xls                                 | readxl         |                | Default |                         |
-| Fixed-width format data             | fwf                                 | readr          | utils          | Default |                         |
-| Fortran data                        | fortran                             | utils          |                | Default | No recognized extension |
-| Google Sheets                       | googlesheets                        | data.table     |                | Default | As comma-separated data |
-| Minitab                             | minitab / mtp                       | foreign        |                | Default |                         |
-| Pipe-separated data                 | psv                                 | data.table     | data.table     | Default |                         |
-| R syntax                            | r                                   | base           | base           | Default |                         |
-| SAS                                 | sas / sas7bdat                      | haven          | haven          | Default | Export is deprecated    |
-| SAS XPORT                           | xport / xpt                         | haven          | haven          | Default |                         |
-| SPSS                                | sav / spss                          | haven          | haven          | Default |                         |
-| SPSS (compressed)                   | zsav                                | haven          | haven          | Default |                         |
-| SPSS Portable                       | por                                 | haven          |                | Default |                         |
-| Saved R objects                     | rda / rdata                         | base           | base           | Default |                         |
-| Serialized R objects                | rds                                 | base           | base           | Default |                         |
-| Stata                               | dta / stata                         | haven          | haven          | Default |                         |
-| Systat                              | syd / systat                        | foreign        |                | Default |                         |
-| Tab-separated data                  | / tsv / txt                         | data.table     | data.table     | Default |                         |
-| Text Representations of R Objects   | dump                                | base           | base           | Default |                         |
-| Weka Attribute-Relation File Format | arff / weka                         | foreign        | foreign        | Default |                         |
-| XBASE database files                | dbf                                 | foreign        | foreign        | Default |                         |
-| Apache Arrow (Parquet)              | parquet                             | arrow          | arrow          | Suggest |                         |
-| Clipboard                           | clipboard                           | clipr          | clipr          | Suggest | default is tsv          |
-| EViews                              | eviews / wf1                        | hexView        |                | Suggest |                         |
-| Fast Storage                        | fst                                 | fst            | fst            | Suggest |                         |
-| Feather R/Python interchange format | feather                             | arrow          | arrow          | Suggest |                         |
-| Graphpad Prism                      | pzfx                                | pzfx           | pzfx           | Suggest |                         |
-| HTML Tables                         | htm / html                          | xml2           | xml2           | Suggest |                         |
-| JSON                                | json                                | jsonlite       | jsonlite       | Suggest |                         |
-| Matlab                              | mat / matlab                        | rmatio         | rmatio         | Suggest |                         |
-| OpenDocument Spreadsheet            | ods                                 | readODS        | readODS        | Suggest |                         |
-| OpenDocument Spreadsheet (Flat)     | fods                                | readODS        | readODS        | Suggest |                         |
-| Serialized R objects (Quick)        | qs                                  | qs             | qs             | Suggest |                         |
-| Shallow XML documents               | xml                                 | xml2           | xml2           | Suggest |                         |
-| YAML                                | yaml / yml                          | yaml           | yaml           | Suggest |                         |
+| Name                                | Extensions / “format”               | Import Package | Export Package | Type    | Note                           |
+| :---------------------------------- | :---------------------------------- | :------------- | :------------- | :------ | :----------------------------- |
+| Archive files (handled by tar)      | tar / tar.gz / tgz / tar.bz2 / tbz2 | utils          | utils          | Default |                                |
+| Bzip2                               | bz2 / bzip2                         | base           | base           | Default |                                |
+| Gzip                                | gz / gzip                           | base           | base           | Default |                                |
+| Zip files                           | zip                                 | utils          | utils          | Default |                                |
+| Ambiguous file format               | dat                                 | data.table     |                | Default | Attempt as delimited text data |
+| CSVY (CSV + YAML metadata header)   | csvy                                | data.table     | data.table     | Default |                                |
+| Comma-separated data                | csv                                 | data.table     | data.table     | Default |                                |
+| Comma-separated data (European)     | csv2                                | data.table     | data.table     | Default |                                |
+| Data Interchange Format             | dif                                 | utils          |                | Default |                                |
+| Epiinfo                             | epiinfo / rec                       | foreign        |                | Default |                                |
+| Excel                               | excel / xlsx                        | readxl         | writexl        | Default |                                |
+| Excel (Legacy)                      | xls                                 | readxl         |                | Default |                                |
+| Fixed-width format data             | fwf                                 | readr          | utils          | Default |                                |
+| Fortran data                        | fortran                             | utils          |                | Default | No recognized extension        |
+| Google Sheets                       | googlesheets                        | data.table     |                | Default | As comma-separated data        |
+| Minitab                             | minitab / mtp                       | foreign        |                | Default |                                |
+| Pipe-separated data                 | psv                                 | data.table     | data.table     | Default |                                |
+| R syntax                            | r                                   | base           | base           | Default |                                |
+| SAS                                 | sas / sas7bdat                      | haven          | haven          | Default | Export is deprecated           |
+| SAS XPORT                           | xport / xpt                         | haven          | haven          | Default |                                |
+| SPSS                                | sav / spss                          | haven          | haven          | Default |                                |
+| SPSS (compressed)                   | zsav                                | haven          | haven          | Default |                                |
+| SPSS Portable                       | por                                 | haven          |                | Default |                                |
+| Saved R objects                     | rda / rdata                         | base           | base           | Default |                                |
+| Serialized R objects                | rds                                 | base           | base           | Default |                                |
+| Stata                               | dta / stata                         | haven          | haven          | Default |                                |
+| Systat                              | syd / systat                        | foreign        |                | Default |                                |
+| Tab-separated data                  | / tsv / txt                         | data.table     | data.table     | Default |                                |
+| Text Representations of R Objects   | dump                                | base           | base           | Default |                                |
+| Weka Attribute-Relation File Format | arff / weka                         | foreign        | foreign        | Default |                                |
+| XBASE database files                | dbf                                 | foreign        | foreign        | Default |                                |
+| Apache Arrow (Parquet)              | parquet                             | arrow          | arrow          | Suggest |                                |
+| Clipboard                           | clipboard                           | clipr          | clipr          | Suggest | default is tsv                 |
+| EViews                              | eviews / wf1                        | hexView        |                | Suggest |                                |
+| Fast Storage                        | fst                                 | fst            | fst            | Suggest |                                |
+| Feather R/Python interchange format | feather                             | arrow          | arrow          | Suggest |                                |
+| Graphpad Prism                      | pzfx                                | pzfx           | pzfx           | Suggest |                                |
+| HTML Tables                         | htm / html                          | xml2           | xml2           | Suggest |                                |
+| JSON                                | json                                | jsonlite       | jsonlite       | Suggest |                                |
+| Matlab                              | mat / matlab                        | rmatio         | rmatio         | Suggest |                                |
+| OpenDocument Spreadsheet            | ods                                 | readODS        | readODS        | Suggest |                                |
+| OpenDocument Spreadsheet (Flat)     | fods                                | readODS        | readODS        | Suggest |                                |
+| Serialized R objects (Quick)        | qs                                  | qs             | qs             | Suggest |                                |
+| Shallow XML documents               | xml                                 | xml2           | xml2           | Suggest |                                |
+| YAML                                | yaml / yml                          | yaml           | yaml           | Suggest |                                |
 
 Additionally, any format that is not supported by **rio** but that has a
 known R implementation will produce an informative error message
diff --git a/data-raw/single.json b/data-raw/single.json
index 5da8dfd..0af42e4 100644
--- a/data-raw/single.json
+++ b/data-raw/single.json
@@ -781,6 +781,15 @@
         "import_function": "data.table::fread",
         "export_function": "data.table::fwrite",
         "note": ""
+    },
+    {
+        "input": "dat",
+        "format": "dat",
+        "type": "import",
+        "format_name": "Ambiguous file format",
+        "import_function": "data.table::fread",
+        "export_function": "",
+        "note": "Attempt as delimited text data"
     }
 ]
 
diff --git a/tests/testthat/test_format_csv.R b/tests/testthat/test_format_csv.R
index c872de6..81508e7 100644
--- a/tests/testthat/test_format_csv.R
+++ b/tests/testthat/test_format_csv.R
@@ -64,3 +64,13 @@ test_that("fread is deprecated", {
         lifecycle::expect_deprecated(import(iris_file, fread = FALSE))
     })
 })
+
+test_that("dat (ambiguous file format) will be attempted #430", {
+    withr::with_tempfile("iris_file", fileext = ".dat", code = {
+        readr::write_delim(iris, file = iris_file)
+        expect_error(suppressMessages(import(iris_file)), NA)
+        expect_message(z <- import(iris_file))
+        ## export is not supported though
+        expect_error(export(iris, iris_file))
+    })
+})