[from|to]csv additions/refactoring.

Introduced flag to tell `from-to` / `to-csv` whether we want headers parsed and/or written.

src/commands/from_csv.rs

@@ -5,26 +5,32 @@ use csv::ReaderBuilder;
 
 pub struct FromCSV;
 
-impl WholeStreamCommand for FromCSV {
+#[derive(Deserialize)]
-    fn run(
+pub struct FromCSVArgs {
-        &self,
+    headerless: bool,
-        args: CommandArgs,
-        registry: &CommandRegistry,
-    ) -> Result<OutputStream, ShellError> {
-        from_csv(args, registry)
 }
 
+impl WholeStreamCommand for FromCSV {
     fn name(&self) -> &str {
         "from-csv"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-csv")
+        Signature::build("from-csv").switch("headerless")
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, from_csv)?.run()
     }
 }
 
 pub fn from_csv_string_to_value(
     s: String,
+    headerless: bool,
     tag: impl Into<Tag>,
 ) -> Result<Tagged<Value>, csv::Error> {
     let mut reader = ReaderBuilder::new()
@@ -39,10 +45,14 @@ pub fn from_csv_string_to_value(
     if let Some(result) = iter.next() {
         let line = result?;
 
-        for item in line.iter() {
+        for (idx, item) in line.iter().enumerate() {
+            if headerless {
+                fields.push_back(format!("Column{}", idx + 1));
+            } else {
                 fields.push_back(item.to_string());
             }
         }
+    }
 
     loop {
         if let Some(row_values) = iter.next() {
@@ -66,10 +76,13 @@ pub fn from_csv_string_to_value(
     Ok(Tagged::from_item(Value::List(rows), tag))
 }
 
-fn from_csv(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+fn from_csv(
-    let args = args.evaluate_once(registry)?;
+    FromCSVArgs {
-    let span = args.name_span();
+        headerless: skip_headers,
-    let input = args.input;
+    }: FromCSVArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let name_span = name;
 
     let stream = async_stream_block! {
         let values: Vec<Tagged<Value>> = input.values.collect().await;
@@ -88,7 +101,7 @@ fn from_csv(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStrea
                 _ => yield Err(ShellError::labeled_error_with_secondary(
                     "Expected a string from pipeline",
                     "requires string input",
-                    span,
+                    name_span,
                     "value originates from here",
                     value_tag.span,
                 )),
@@ -96,7 +109,7 @@ fn from_csv(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStrea
             }
         }
 
-        match from_csv_string_to_value(concat_string, span) {
+        match from_csv_string_to_value(concat_string, skip_headers, name_span) {
             Ok(x) => match x {
                 Tagged { item: Value::List(list), .. } => {
                     for l in list {
@@ -109,7 +122,7 @@ fn from_csv(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStrea
                 yield Err(ShellError::labeled_error_with_secondary(
                     "Could not parse as CSV",
                     "input cannot be parsed as CSV",
-                    span,
+                    name_span,
                     "value originates from here",
                     last_tag.span,
                 ))

src/commands/open.rs

@@ -428,6 +428,7 @@ pub fn parse_string_as_value(
     match extension {
         Some(x) if x == "csv" => crate::commands::from_csv::from_csv_string_to_value(
             contents,
+            false,
             contents_tag,
         )
         .map_err(move |_| {

src/commands/to_csv.rs

@@ -5,21 +5,26 @@ use csv::WriterBuilder;
 
 pub struct ToCSV;
 
-impl WholeStreamCommand for ToCSV {
+#[derive(Deserialize)]
-    fn run(
+pub struct ToCSVArgs {
-        &self,
+    headerless: bool,
-        args: CommandArgs,
-        registry: &CommandRegistry,
-    ) -> Result<OutputStream, ShellError> {
-        to_csv(args, registry)
 }
 
+impl WholeStreamCommand for ToCSV {
     fn name(&self) -> &str {
         "to-csv"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("to-csv")
+        Signature::build("to-csv").switch("headerless")
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, to_csv)?.run()
     }
 }
 
@@ -27,6 +32,9 @@ pub fn value_to_csv_value(v: &Value) -> Value {
     match v {
         Value::Primitive(Primitive::String(s)) => Value::Primitive(Primitive::String(s.clone())),
         Value::Primitive(Primitive::Nothing) => Value::Primitive(Primitive::Nothing),
+        Value::Primitive(Primitive::Boolean(b)) => Value::Primitive(Primitive::Boolean(b.clone())),
+        Value::Primitive(Primitive::Bytes(b)) => Value::Primitive(Primitive::Bytes(b.clone())),
+        Value::Primitive(Primitive::Date(d)) => Value::Primitive(Primitive::Date(d.clone())),
         Value::Object(o) => Value::Object(o.clone()),
         Value::List(l) => Value::List(l.clone()),
         Value::Block(_) => Value::Primitive(Primitive::Nothing),
@@ -34,9 +42,20 @@ pub fn value_to_csv_value(v: &Value) -> Value {
     }
 }
 
+fn to_string_helper(v: &Value) -> Result<String, Box<dyn std::error::Error>> {
+    match v {
+        Value::Primitive(Primitive::Date(d)) => Ok(d.to_string()),
+        Value::Primitive(Primitive::Bytes(b)) => Ok(format!("{}", *b as u64)),
+        Value::Primitive(Primitive::Boolean(_)) => Ok(v.as_string()?),
+        Value::List(_) => return Ok(String::from("[list list]")),
+        Value::Object(_) => return Ok(String::from("[object]")),
+        Value::Primitive(Primitive::String(s)) => return Ok(s.to_string()),
+        _ => return Err("Bad input".into()),
+    }
+}
+
 pub fn to_string(v: &Value) -> Result<String, Box<dyn std::error::Error>> {
     match v {
-        Value::List(_l) => return Ok(String::from("[list list]")),
         Value::Object(o) => {
             let mut wtr = WriterBuilder::new().from_writer(vec![]);
             let mut fields: VecDeque<String> = VecDeque::new();
@@ -44,7 +63,7 @@ pub fn to_string(v: &Value) -> Result<String, Box<dyn std::error::Error>> {
 
             for (k, v) in o.entries.iter() {
                 fields.push_back(k.clone());
-                values.push_back(to_string(&v)?);
+                values.push_back(to_string_helper(&v)?);
             }
 
             wtr.write_record(fields).expect("can not write.");
@@ -52,22 +71,31 @@ pub fn to_string(v: &Value) -> Result<String, Box<dyn std::error::Error>> {
 
             return Ok(String::from_utf8(wtr.into_inner()?)?);
         }
-        Value::Primitive(Primitive::String(s)) => return Ok(s.to_string()),
+        _ => return to_string_helper(&v),
-        _ => return Err("Bad input".into()),
     }
 }
 
-fn to_csv(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+fn to_csv(
-    let args = args.evaluate_once(registry)?;
+    ToCSVArgs { headerless }: ToCSVArgs,
-    let name_span = args.name_span();
+    RunnableContext { input, name, .. }: RunnableContext,
-    let out = args.input;
+) -> Result<OutputStream, ShellError> {
+    let name_span = name;
+    let out = input;
 
     Ok(out
         .values
         .map(move |a| match to_string(&value_to_csv_value(&a.item)) {
-            Ok(x) => ReturnSuccess::value(
+            Ok(x) => {
-                Value::Primitive(Primitive::String(x)).simple_spanned(name_span),
+                let converted = if headerless {
-            ),
+                    x.lines().skip(1).collect()
+                } else {
+                    x
+                };
+
+                ReturnSuccess::value(
+                    Value::Primitive(Primitive::String(converted)).simple_spanned(name_span),
+                )
+            }
             _ => Err(ShellError::labeled_error_with_secondary(
                 "Expected an object with CSV-compatible structure from pipeline",
                 "requires CSV-compatible input",

tests/command_open_tests.rs

@@ -0,0 +1,114 @@
+mod helpers;
+
+use helpers::{in_directory as cwd, Playground, Stub::*};
+
+#[test]
+fn recognizes_csv() {
+    Playground::setup_for("open_recognizes_csv_test").with_files(vec![FileWithContentToBeTrimmed(
+        "nu.zion.csv",
+        r#"
+            author,lang,source
+            Jonathan Turner,Rust,New Zealand
+            Andres N. Robalino,Rust,Ecuador
+            Yehuda Katz,Rust,Estados Unidos
+        "#,
+    )]);
+
+    nu!(
+        output,
+        cwd("tests/fixtures/nuplayground/open_recognizes_csv_test"),
+        "open nu.zion.csv | where author == \"Andres N. Robalino\" | get source | echo $it"
+    );
+
+    assert_eq!(output, "Ecuador");
+}
+
+#[test]
+fn open_can_parse_bson_1() {
+    nu!(
+        output,
+        cwd("tests/fixtures/formats"),
+        "open sample.bson | nth 0 | get b | echo $it"
+    );
+
+    assert_eq!(output, "hello");
+}
+
+#[test]
+fn open_can_parse_bson_2() {
+    nu!(
+        output,
+        cwd("tests/fixtures/formats"),
+        "open sample.bson | nth 6 | get b | get '$binary_subtype' | echo $it "
+    );
+
+    assert_eq!(output, "function");
+}
+
+#[test]
+fn open_can_parse_toml() {
+    nu!(
+        output,
+        cwd("tests/fixtures/formats"),
+        "open cargo_sample.toml | get package.edition | echo $it"
+    );
+
+    assert_eq!(output, "2018");
+}
+
+#[test]
+fn open_can_parse_json() {
+    nu!(output,
+        cwd("tests/fixtures/formats"),
+        "open sgml_description.json | get glossary.GlossDiv.GlossList.GlossEntry.GlossSee | echo $it"
+    );
+
+    assert_eq!(output, "markup")
+}
+
+#[test]
+fn open_can_parse_xml() {
+    nu!(
+        output,
+        cwd("tests/fixtures/formats"),
+        "open jonathan.xml | get rss.channel.item.link | echo $it"
+    );
+
+    assert_eq!(
+        output,
+        "http://www.jonathanturner.org/2015/10/off-to-new-adventures.html"
+    )
+}
+
+#[test]
+fn open_can_parse_ini() {
+    nu!(
+        output,
+        cwd("tests/fixtures/formats"),
+        "open sample.ini | get SectionOne.integer | echo $it"
+    );
+
+    assert_eq!(output, "1234")
+}
+
+#[test]
+fn open_can_parse_utf16_ini() {
+    nu!(
+        output,
+        cwd("tests/fixtures/formats"),
+        "open utf16.ini | get .ShellClassInfo | get IconIndex | echo $it"
+    );
+
+    assert_eq!(output, "-236")
+}
+
+#[test]
+fn errors_if_file_not_found() {
+    nu_error!(
+        output,
+        cwd("tests/fixtures/formats"),
+        "open i_dont_exist.txt | echo $it"
+    );
+
+    assert!(output.contains("File could not be opened"));
+}

tests/commands_test.rs

@@ -13,108 +13,6 @@ fn lines() {
     assert_eq!(output, "rustyline");
 }
 
-#[test]
-fn open_can_parse_csv() {
-    nu!(
-        output,
-        cwd("tests/fixtures/formats"),
-        "open caco3_plastics.csv | first 1 | get origin | echo $it"
-    );
-
-    assert_eq!(output, "SPAIN");
-}
-
-#[test]
-fn open_can_parse_bson_1() {
-    nu!(
-        output,
-        cwd("tests/fixtures/formats"),
-        "open sample.bson | nth 0 | get b | echo $it"
-    );
-
-    assert_eq!(output, "hello");
-}
-
-#[test]
-fn open_can_parse_bson_2() {
-    nu!(
-        output,
-        cwd("tests/fixtures/formats"),
-        "open sample.bson | nth 6 | get b | get '$binary_subtype' | echo $it "
-    );
-
-    assert_eq!(output, "function");
-}
-
-#[test]
-fn open_can_parse_toml() {
-    nu!(
-        output,
-        cwd("tests/fixtures/formats"),
-        "open cargo_sample.toml | get package.edition | echo $it"
-    );
-
-    assert_eq!(output, "2018");
-}
-
-#[test]
-fn open_can_parse_json() {
-    nu!(output,
-        cwd("tests/fixtures/formats"),
-        "open sgml_description.json | get glossary.GlossDiv.GlossList.GlossEntry.GlossSee | echo $it"
-    );
-
-    assert_eq!(output, "markup")
-}
-
-#[test]
-fn open_can_parse_xml() {
-    nu!(
-        output,
-        cwd("tests/fixtures/formats"),
-        "open jonathan.xml | get rss.channel.item.link | echo $it"
-    );
-
-    assert_eq!(
-        output,
-        "http://www.jonathanturner.org/2015/10/off-to-new-adventures.html"
-    )
-}
-
-#[test]
-fn open_can_parse_ini() {
-    nu!(
-        output,
-        cwd("tests/fixtures/formats"),
-        "open sample.ini | get SectionOne.integer | echo $it"
-    );
-
-    assert_eq!(output, "1234")
-}
-
-#[test]
-fn open_can_parse_utf16_ini() {
-    nu!(
-        output,
-        cwd("tests/fixtures/formats"),
-        "open utf16.ini | get .ShellClassInfo | get IconIndex | echo $it"
-    );
-
-    assert_eq!(output, "-236")
-}
-
-#[test]
-fn open_error_if_file_not_found() {
-    nu_error!(
-        output,
-        cwd("tests/fixtures/formats"),
-        "open i_dont_exist.txt | echo $it"
-    );
-
-    assert!(output.contains("File could not be opened"));
-}
-
-#[test]
 fn save_figures_out_intelligently_where_to_write_out_with_metadata() {
     let sandbox = Playground::setup_for("save_smart_test")
         .with_files(vec![FileWithContent(

tests/filters_test.rs

@@ -1,6 +1,6 @@
 mod helpers;
 
-use helpers::in_directory as cwd;
+use helpers::{in_directory as cwd, Playground, Stub::*};
 
 #[test]
 fn can_convert_table_to_csv_text_and_from_csv_text_back_into_table() {
@@ -13,6 +13,88 @@ fn can_convert_table_to_csv_text_and_from_csv_text_back_into_table() {
     assert_eq!(output, "SPAIN");
 }
 
+#[test]
+fn converts_structured_table_to_csv_text() {
+    Playground::setup_for("filter_to_csv_test_1").with_files(vec![FileWithContentToBeTrimmed(
+        "sample.csv",
+        r#"
+            importer,shipper,tariff_item,name,origin
+            Plasticos Rival,Reverte,2509000000,Calcium carbonate,Spain
+            Tigre Ecuador,OMYA Andina,3824909999,Calcium carbonate,Colombia
+        "#,
+    )]);
+
+    nu!(
+        output,
+        cwd("tests/fixtures/nuplayground/filter_to_csv_test_1"),
+        "open sample.csv --raw | lines | split-column \",\" a b c d origin  | last 1 | to-csv | lines | nth 1 | echo \"$it\""
+    );
+
+    assert!(output.contains("Tigre Ecuador,OMYA Andina,3824909999,Calcium carbonate,Colombia"));
+}
+
+#[test]
+fn converts_structured_table_to_csv_text_skipping_headers_after_conversion() {
+    Playground::setup_for("filter_to_csv_test_2").with_files(vec![FileWithContentToBeTrimmed(
+        "sample.csv",
+        r#"
+            importer,shipper,tariff_item,name,origin
+            Plasticos Rival,Reverte,2509000000,Calcium carbonate,Spain
+            Tigre Ecuador,OMYA Andina,3824909999,Calcium carbonate,Colombia
+        "#,
+    )]);
+
+    nu!(
+        output,
+        cwd("tests/fixtures/nuplayground/filter_to_csv_test_2"),
+        "open sample.csv --raw | lines | split-column \",\" a b c d origin  | last 1 | to-csv --headerless | echo \"$it\""
+    );
+
+    assert!(output.contains("Tigre Ecuador,OMYA Andina,3824909999,Calcium carbonate,Colombia"));
+}
+
+#[test]
+fn converts_from_csv_text_to_structured_table() {
+    Playground::setup_for("filter_from_csv_test_1").with_files(vec![FileWithContentToBeTrimmed(
+        "los_tres_amigos.txt",
+        r#"
+            first_name,last_name,rusty_luck
+            Andrés,Robalino,1
+            Jonathan,Turner,1
+            Yehuda,Katz,1
+        "#,
+    )]);
+
+    nu!(
+        output,
+        cwd("tests/fixtures/nuplayground/filter_from_csv_test_1"),
+        "open los_tres_amigos.txt | from-csv | get rusty_luck | str --to-int | sum | echo $it"
+    );
+
+    assert_eq!(output, "3");
+}
+
+#[test]
+fn converts_from_csv_text_skipping_headers_to_structured_table() {
+    Playground::setup_for("filter_from_csv_test_2").with_files(vec![FileWithContentToBeTrimmed(
+        "los_tres_amigos.txt",
+        r#"
+            first_name,last_name,rusty_luck
+            Andrés,Robalino,1
+            Jonathan,Turner,1
+            Yehuda,Katz,1
+        "#,
+    )]);
+
+    nu!(
+        output,
+        cwd("tests/fixtures/nuplayground/filter_from_csv_test_2"),
+        "open los_tres_amigos.txt | from-csv --headerless | get Column3 | str --to-int | sum | echo $it"
+    );
+
+    assert_eq!(output, "3");
+}
+
 #[test]
 fn can_convert_table_to_json_text_and_from_json_text_back_into_table() {
     nu!(

tests/helpers/mod.rs

@@ -79,6 +79,7 @@ macro_rules! nu_error {
 
 pub enum Stub<'a> {
     FileWithContent(&'a str, &'a str),
+    FileWithContentToBeTrimmed(&'a str, &'a str),
     EmptyFile(&'a str),
 }
 
@@ -124,14 +125,25 @@ impl Playground {
     }
 
     pub fn with_files(&mut self, files: Vec<Stub>) -> &mut Self {
+        let endl = line_ending();
+
         files
             .iter()
             .map(|f| {
                 let mut path = PathBuf::from(&self.cwd);
 
                 let (file_name, contents) = match *f {
-                    Stub::EmptyFile(name) => (name, "fake data"),
+                    Stub::EmptyFile(name) => (name, "fake data".to_string()),
-                    Stub::FileWithContent(name, content) => (name, content),
+                    Stub::FileWithContent(name, content) => (name, content.to_string()),
+                    Stub::FileWithContentToBeTrimmed(name, content) => (
+                        name,
+                        content
+                            .lines()
+                            .skip(1)
+                            .map(|line| line.trim())
+                            .collect::<Vec<&str>>()
+                            .join(&endl),
+                    ),
                 };
 
                 path.push(file_name);
@@ -176,6 +188,18 @@ pub fn file_contents(full_path: &str) -> String {
     contents
 }
 
+pub fn line_ending() -> String {
+    #[cfg(windows)]
+    {
+        String::from("\r\n")
+    }
+
+    #[cfg(not(windows))]
+    {
+        String::from("\n")
+    }
+}
+
 pub fn normalize_string(input: &str) -> String {
     #[cfg(windows)]
     {