input refactor

resources/test/inputskiptest.csv

@@ -0,0 +1,13 @@
+# test file to see how skiplines work"
+! this is another comment before the header"
+# DATA DICTIONARY"
+! column1 - alphabetic; id of the column"
+% column2 - numeric; just a number"
+column1,column2
+a,1
+b,2
+c,3
+d,4
+e,5
+// this is an epilog line
+# and another one

src/cmd/input.rs

@@ -4,31 +4,34 @@ use crate::CliResult;
 use serde::Deserialize;
 
 static USAGE: &str = r#"
-Read CSV data with special quoting and line-skipping rules.
+Read CSV data with special quoting, trimming and line-skipping rules.
 
 Generally, all qsv commands support basic options like specifying the delimiter
 used in CSV data. This does not cover all possible types of CSV data. For
 example, some CSV files don't use '"' for quotes or use different escaping
 styles.
 
-Also, CSVs that are technically malformed with preamble lines can be converted
-into a format qsv can handle with the --skip-lines option.
+Also, CSVs with preamble lines can be have the preamble skipped with the --skip-lines 
+option. Similarly, --skip-lastlines allows epilog lines to be skipped.
 
 Usage:
     qsv input [options] [<input>]
 
 input options:
-    --quote <arg>          The quote character to use. [default: "]
-    --escape <arg>         The escape character to use. When not specified,
-                           quotes are escaped by doubling them.
-    --no-quoting           Disable quoting completely.
-    --skip-lines <arg>     The number of lines to skip.
+    --quote <arg>            The quote character to use. [default: "]
+    --escape <arg>           The escape character to use. When not specified,
+                             quotes are escaped by doubling them.
+    --no-quoting             Disable quoting completely.
+    --skip-lines <arg>       The number of preamble lines to skip.
+    --skip-lastlines <arg>   The number of epilog lines to skip.
+    --trim-headers           Trim leading & trailing whitespace from header values.
+    --trim-fields            Trim leading & trailing whitespace from field values.
 
 Common options:
-    -h, --help             Display this message
-    -o, --output <file>    Write output to <file> instead of stdout.
-    -d, --delimiter <arg>  The field delimiter for reading CSV data.
-                           Must be a single character. (default: ,)
+    -h, --help               Display this message
+    -o, --output <file>      Write output to <file> instead of stdout.
+    -d, --delimiter <arg>    The field delimiter for reading CSV data.
+                             Must be a single character. (default: ,)
 "#;
 
 #[derive(Deserialize)]
@@ -39,15 +42,27 @@ struct Args {
     flag_quote: Delimiter,
     flag_escape: Option<Delimiter>,
     flag_no_quoting: bool,
-    flag_skip_lines: Option<usize>,
+    flag_skip_lines: Option<u64>,
+    flag_skip_lastlines: Option<u64>,
+    flag_trim_headers: bool,
+    flag_trim_fields: bool,
 }
 
 pub fn run(argv: &[&str]) -> CliResult<()> {
     let args: Args = util::get_args(USAGE, argv)?;
+
+    let trim_setting = match (args.flag_trim_headers, args.flag_trim_fields) {
+        (false, false) => csv::Trim::None,
+        (true, true) => csv::Trim::All,
+        (true, false) => csv::Trim::Headers,
+        (false, true) => csv::Trim::Fields,
+    };
+
     let mut rconfig = Config::new(&args.arg_input)
         .delimiter(args.flag_delimiter)
         .no_headers(true)
-        .quote(args.flag_quote.as_byte());
+        .quote(args.flag_quote.as_byte())
+        .trim(trim_setting);
     let wconfig = Config::new(&args.flag_output);
 
     if let Some(escape) = args.flag_escape {
@@ -56,6 +71,19 @@ pub fn run(argv: &[&str]) -> CliResult<()> {
     if args.flag_no_quoting {
         rconfig = rconfig.quoting(false);
     }
+    if args.flag_skip_lines.is_some() || args.flag_skip_lastlines.is_some() {
+        rconfig = rconfig.flexible(true);
+    }
+
+    let mut total_lines = 0_u64;
+    if let Some(skip_llines) = args.flag_skip_lastlines {
+        let row_count = util::count_rows(&rconfig);
+        if skip_llines > row_count {
+            return fail!("--skip-lastlines: {skip_llines} is greater than row_count: {rowcount}.");
+        } else {
+            total_lines = row_count - skip_llines;
+        }
+    }
 
     let mut rdr = rconfig.reader()?;
     let mut wtr = wconfig.writer()?;
@@ -64,9 +92,27 @@ pub fn run(argv: &[&str]) -> CliResult<()> {
         for _i in 1..=skip_lines {
             rdr.read_byte_record(&mut row)?;
         }
+        if total_lines.saturating_sub(skip_lines) > 0 {
+            total_lines -= skip_lines;
+        }
+    }
+    // the first rdr record is the header, since
+    // we have no_headers = true, we manually trim the first record
+    if trim_setting == csv::Trim::Headers || trim_setting == csv::Trim::All {
+        rdr.read_byte_record(&mut row)?;
+        row.trim();
+        wtr.write_record(&row)?;
     }
+
+    let mut i = 1_u64;
     while rdr.read_byte_record(&mut row)? {
         wtr.write_record(&row)?;
+        if total_lines > 0 {
+            i += 1;
+            if i > total_lines {
+                break;
+            }
+        }
     }
     wtr.flush()?;
     Ok(())

src/config.rs

@@ -80,6 +80,7 @@ pub struct Config {
     double_quote: bool,
     escape: Option<u8>,
     quoting: bool,
+    trim: csv::Trim,
     autoindex: bool,
     checkutf8: bool,
 }
@@ -143,6 +144,7 @@ impl Config {
             double_quote: true,
             escape: None,
             quoting: true,
+            trim: csv::Trim::None,
             autoindex: env::var("QSV_AUTOINDEX").is_ok(),
             checkutf8: env::var("QSV_SKIPUTF8_CHECK").is_err(),
         }
@@ -216,6 +218,11 @@ impl Config {
         self
     }
 
+    pub fn trim(mut self, trim_type: csv::Trim) -> Config {
+        self.trim = trim_type;
+        self
+    }
+
     pub fn select(mut self, sel_cols: SelectColumns) -> Config {
         self.select_columns = Some(sel_cols);
         self
@@ -453,6 +460,7 @@ impl Config {
             .escape(self.escape)
             .buffer_capacity(rdr_buffer)
             .comment(rdr_comment)
+            .trim(self.trim)
             .from_reader(rdr)
     }
 

tests/test_comments.rs

@@ -265,3 +265,163 @@ fn test_input_skip_no_line() {
     ];
     assert_eq!(got, expected);
 }
+
+#[test]
+fn test_input_trim_headers() {
+    let wrk = Workdir::new("input_trim_headers");
+    wrk.create(
+        "data.csv",
+        vec![
+            svec!["   column1   ", "  column2   "],
+            svec!["  a", "1"],
+            svec!["c  ", "3"],
+            svec!["e", "5   "],
+        ],
+    );
+    let mut cmd = wrk.command("input");
+    cmd.arg("--trim-headers").arg("data.csv");
+
+    let got: Vec<Vec<String>> = wrk.read_stdout(&mut cmd);
+    let expected = vec![
+        svec!["column1", "column2"],
+        svec!["  a", "1"],
+        svec!["c  ", "3"],
+        svec!["e", "5   "],
+    ];
+    assert_eq!(got, expected);
+}
+
+#[test]
+fn test_input_trim_fields() {
+    let wrk = Workdir::new("input_trim_fields");
+    wrk.create(
+        "data.csv",
+        vec![
+            svec!["column1   ", "column2   "],
+            svec!["   a", "  1"],
+            svec!["c   ", "3  "],
+            svec!["   e   ", "  5"],
+        ],
+    );
+    let mut cmd = wrk.command("input");
+    cmd.arg("--trim-fields").arg("data.csv");
+
+    let got: Vec<Vec<String>> = wrk.read_stdout(&mut cmd);
+    let expected = vec![
+        svec!["column1   ", "column2   "],
+        svec!["a", "1"],
+        svec!["c", "3"],
+        svec!["e", "5"],
+    ];
+    assert_eq!(got, expected);
+}
+
+#[test]
+fn test_input_trim_headers_fields() {
+    let wrk = Workdir::new("input_trim_headers_fields");
+    wrk.create(
+        "data.csv",
+        vec![
+            svec!["   column1   ", "   column2   "],
+            svec!["   a", "  1"],
+            svec!["c   ", "3  "],
+            svec!["   e   ", "  5"],
+        ],
+    );
+    let mut cmd = wrk.command("input");
+    cmd.arg("--trim-headers")
+        .arg("--trim-fields")
+        .arg("data.csv");
+
+    let got: Vec<Vec<String>> = wrk.read_stdout(&mut cmd);
+    let expected = vec![
+        svec!["column1", "column2"],
+        svec!["a", "1"],
+        svec!["c", "3"],
+        svec!["e", "5"],
+    ];
+    assert_eq!(got, expected);
+}
+
+#[test]
+fn test_input_skip_lastlines() {
+    let wrk = Workdir::new("input_skip_lastlines");
+    wrk.create(
+        "data.csv",
+        vec![
+            svec!["column1", "column2"],
+            svec!["a", "1"],
+            svec!["b", "2"],
+            svec!["c", "3"],
+            svec!["d", "4"],
+            svec!["e", "5"],
+        ],
+    );
+    let mut cmd = wrk.command("input");
+    cmd.arg("--skip-lastlines").arg("2").arg("data.csv");
+
+    let got: Vec<Vec<String>> = wrk.read_stdout(&mut cmd);
+    let expected = vec![
+        svec!["column1", "column2"],
+        svec!["a", "1"],
+        svec!["b", "2"],
+        svec!["c", "3"],
+    ];
+    assert_eq!(got, expected);
+}
+
+#[test]
+fn test_input_skip_lines_both() {
+    let wrk = Workdir::new("input_skip_lines_both");
+    wrk.create(
+        "data.csv",
+        vec![
+            svec!["#column1", "column2"],
+            svec!["! column1", "column2"],
+            svec!["column1", "column2"],
+            svec!["a", "1"],
+            svec!["b", "2"],
+            svec!["c", "3"],
+            svec!["d", "4"],
+            svec!["e", "5"],
+        ],
+    );
+    let mut cmd = wrk.command("input");
+    cmd.arg("--skip-lastlines")
+        .arg("2")
+        .arg("--skip-lines")
+        .arg("2")
+        .arg("data.csv");
+
+    let got: Vec<Vec<String>> = wrk.read_stdout(&mut cmd);
+    let expected = vec![
+        svec!["column1", "column2"],
+        svec!["a", "1"],
+        svec!["b", "2"],
+        svec!["c", "3"],
+    ];
+    assert_eq!(got, expected);
+}
+
+#[test]
+fn test_input_both_skip_flexible() {
+    let wrk = Workdir::new("test_input_both_skip_flexible");
+
+    let test_file = wrk.load_test_file("inputskiptest.csv");
+
+    let mut cmd = wrk.command("input");
+    cmd.arg("--skip-lastlines")
+        .arg("4")
+        .arg("--skip-lines")
+        .arg("5")
+        .arg(test_file);
+
+    let got: Vec<Vec<String>> = wrk.read_stdout(&mut cmd);
+    let expected = vec![
+        svec!["column1", "column2"],
+        svec!["a", "1"],
+        svec!["b", "2"],
+        svec!["c", "3"],
+    ];
+    assert_eq!(got, expected);
+}