Minimal markdown syntax per element support. (#2997)

crates/nu-command/src/commands.rs

@@ -269,7 +269,7 @@ pub(crate) use to::To;
 pub(crate) use to_csv::ToCSV;
 pub(crate) use to_html::ToHTML;
 pub(crate) use to_json::ToJSON;
-pub(crate) use to_md::ToMarkdown;
+pub(crate) use to_md::Command as ToMarkdown;
 pub(crate) use to_toml::ToTOML;
 pub(crate) use to_tsv::ToTSV;
 pub(crate) use to_url::ToURL;
@@ -327,6 +327,7 @@ mod tests {
             whole_stream_command(StrKebabCase),
             whole_stream_command(StrSnakeCase),
             whole_stream_command(StrScreamingSnakeCase),
+            whole_stream_command(ToMarkdown),
         ]
     }
 

crates/nu-command/src/commands/group_by.rs

@@ -46,13 +46,13 @@ impl WholeStreamCommand for Command {
                 result: Some(vec![UntaggedValue::row(indexmap! {
                     "File".to_string() => UntaggedValue::Table(vec![
                         UntaggedValue::row(indexmap! {
-                                "name".to_string() =>          UntaggedValue::string("Andrés.txt").into(),
+                                "name".to_string() =>          UntaggedValue::string("Andres.txt").into(),
                                 "type".to_string() =>                UntaggedValue::string("File").into(),
                             "chickens".to_string() =>                       UntaggedValue::int(10).into(),
                             "modified".to_string() => date("2019-07-23".tagged_unknown()).unwrap().into(),
                         }).into(),
                         UntaggedValue::row(indexmap! {
-                                "name".to_string() =>          UntaggedValue::string("Andrés.txt").into(),
+                                "name".to_string() =>          UntaggedValue::string("Darren.txt").into(),
                                 "type".to_string() =>                UntaggedValue::string("File").into(),
                             "chickens".to_string() =>                       UntaggedValue::int(20).into(),
                             "modified".to_string() => date("2019-09-24".tagged_unknown()).unwrap().into(),

crates/nu-command/src/commands/move_/command.rs

@@ -54,7 +54,7 @@ impl WholeStreamCommand for Command {
                 example: r#"ls | move type --before name | first"#,
                 result: Some(vec![row! {
                     "type".into() =>         string("File"),
-                    "name".into() =>   string("Andrés.txt"),
+                    "name".into() =>   string("Andres.txt"),
                     "chickens".into() =>            int(10),
                     "modified".into() => date("2019-07-23")
                 }]),
@@ -63,7 +63,7 @@ impl WholeStreamCommand for Command {
                 description: "or move the column \"chickens\" after \"name\"",
                 example: r#"ls | move chickens --after name | first"#,
                 result: Some(vec![row! {
-                    "name".into() =>   string("Andrés.txt"),
+                    "name".into() =>   string("Andres.txt"),
                     "chickens".into() =>            int(10),
                     "type".into() =>         string("File"),
                     "modified".into() => date("2019-07-23")
@@ -74,7 +74,7 @@ impl WholeStreamCommand for Command {
                 example: r#"ls | move name chickens --after type | first"#,
                 result: Some(vec![row! {
                     "type".into() =>         string("File"),
-                    "name".into() =>   string("Andrés.txt"),
+                    "name".into() =>   string("Andres.txt"),
                     "chickens".into() =>            int(10),
                     "modified".into() => date("2019-07-23")
                 }]),

crates/nu-command/src/commands/to_md.rs

@@ -5,25 +5,33 @@ use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
 use nu_protocol::{ReturnSuccess, Signature, UntaggedValue, Value};
 
-pub struct ToMarkdown;
+pub struct Command;
 
 #[derive(Deserialize)]
-pub struct ToMarkdownArgs {
+pub struct Arguments {
     pretty: bool,
+    #[serde(rename = "per-element")]
+    per_element: bool,
 }
 
 #[async_trait]
-impl WholeStreamCommand for ToMarkdown {
+impl WholeStreamCommand for Command {
     fn name(&self) -> &str {
         "to md"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("to md").switch(
+        Signature::build("to md")
+            .switch(
                 "pretty",
                 "Formats the Markdown table to vertically align items",
                 Some('p'),
             )
+            .switch(
+                "per-element",
+                "treat each row as markdown syntax element",
+                Some('e'),
+            )
     }
 
     fn usage(&self) -> &str {
@@ -37,30 +45,116 @@ impl WholeStreamCommand for ToMarkdown {
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {
-                description: "Outputs an unformatted md string representing the contents of ls",
+                description: "Outputs an unformatted table markdown string (default)",
                 example: "ls | to md",
-                result: None,
+                result: Some(vec![Value::from(one(r#"
+                |name|type|chickens|modified|
+                |-|-|-|-|
+                |Andres.txt|File|10|1 year ago|
+                |Jonathan|Dir|5|1 year ago|
+                |Darren.txt|File|20|1 year ago|
+                |Yehuda|Dir|4|1 year ago|
+                "#))]),
             },
             Example {
-                description: "Outputs a formatted md string representing the contents of ls",
+                description: "Optionally, output a formatted markdown string",
-                example: "ls | to md -p",
+                example: "ls | to md --pretty",
-                result: None,
+                result: Some(vec![Value::from(one(r#"
+                    | name       | type | chickens | modified   |
+                    | ---------- | ---- | -------- | ---------- |
+                    | Andres.txt | File | 10       | 1 year ago |
+                    | Jonathan   | Dir  | 5        | 1 year ago |
+                    | Darren.txt | File | 20       | 1 year ago |
+                    | Yehuda     | Dir  | 4        | 1 year ago |
+                    "#))]),
             },
+            Example {
+                description: "Treat each row as a markdown element",
+                example: "echo [[H1]; [\"Welcome to Nushell\"]] | append $(ls | first 2) | to md --per-element --pretty",
+                result: Some(vec![Value::from(one(r#"
+                    # Welcome to Nushell
+                    | name       | type | chickens | modified   |
+                    | ---------- | ---- | -------- | ---------- |
+                    | Andres.txt | File | 10       | 1 year ago |
+                    | Jonathan   | Dir  | 5        | 1 year ago |
+                    "#))]),
+            }
         ]
     }
 }
 
 async fn to_md(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let name_tag = args.call_info.name_tag.clone();
-    let (ToMarkdownArgs { pretty }, input) = args.process().await?;
+    let (arguments, input) = args.process().await?;
-    let input: Vec<Value> = input.collect().await;
-    let headers = nu_protocol::merge_descriptors(&input);
 
+    let input: Vec<Value> = input.collect().await;
+
+    Ok(OutputStream::one(ReturnSuccess::value(
+        UntaggedValue::string(process(&input, arguments)).into_value(if input.is_empty() {
+            name_tag
+        } else {
+            input[0].tag()
+        }),
+    )))
+}
+
+fn process(
+    input: &[Value],
+    Arguments {
+        pretty,
+        per_element,
+    }: Arguments,
+) -> String {
+    if per_element {
+        input
+            .iter()
+            .map(|v| match &v.value {
+                UntaggedValue::Table(values) => table(values, pretty),
+                _ => fragment(v, pretty),
+            })
+            .collect::<String>()
+    } else {
+        table(&input, pretty)
+    }
+}
+
+fn fragment(input: &Value, pretty: bool) -> String {
+    let headers = input.data_descriptors();
+    let mut out = String::new();
+
+    if headers.len() == 1 {
+        let markup = match (&headers[0]).to_ascii_lowercase().as_ref() {
+            "h1" => "# ".to_string(),
+            "h2" => "## ".to_string(),
+            "h3" => "### ".to_string(),
+            "blockquote" => "> ".to_string(),
+
+            _ => return table(&[input.clone()], pretty),
+        };
+
+        out.push_str(&markup);
+        out.push_str(&format_leaf(input.get_data(&headers[0]).borrow()).plain_string(100_000));
+    } else if input.is_row() {
+        let string = match input.row_entries().next() {
+            Some(value) => value.1.as_string().unwrap_or_default(),
+            None => String::from(""),
+        };
+
+        out = format_leaf(&UntaggedValue::from(string)).plain_string(100_000)
+    } else {
+        out = format_leaf(&input.value).plain_string(100_000)
+    }
+
+    out.push('\n');
+    out
+}
+
+fn collect_headers(headers: &[String]) -> (Vec<String>, Vec<usize>) {
     let mut escaped_headers: Vec<String> = Vec::new();
     let mut column_widths: Vec<usize> = Vec::new();
 
     if !headers.is_empty() && (headers.len() > 1 || !headers[0].is_empty()) {
-        for header in &headers {
+        for header in headers {
             let escaped_header_string = htmlescape::encode_minimal(&header);
             column_widths.push(escaped_header_string.len());
             escaped_headers.push(escaped_header_string);
@@ -69,9 +163,17 @@ async fn to_md(args: CommandArgs) -> Result<OutputStream, ShellError> {
         column_widths = vec![0; headers.len()]
     }
 
+    (escaped_headers, column_widths)
+}
+
+fn table(input: &[Value], pretty: bool) -> String {
+    let headers = nu_protocol::merge_descriptors(&input);
+
+    let (escaped_headers, mut column_widths) = collect_headers(&headers);
+
     let mut escaped_rows: Vec<Vec<String>> = Vec::new();
 
-    for row in &input {
+    for row in input {
         let mut escaped_row: Vec<String> = Vec::new();
 
         match row.value.clone() {
@@ -108,9 +210,7 @@ async fn to_md(args: CommandArgs) -> Result<OutputStream, ShellError> {
             .to_string()
     };
 
-    Ok(OutputStream::one(ReturnSuccess::value(
+    output_string
-        UntaggedValue::string(output_string).into_value(name_tag),
-    )))
 }
 
 fn get_output_string(
@@ -201,15 +301,78 @@ fn get_padded_string(text: String, desired_length: usize, padding_character: cha
     )
 }
 
+fn one(string: &str) -> String {
+    string
+        .lines()
+        .skip(1)
+        .map(|line| line.trim())
+        .collect::<Vec<&str>>()
+        .join("\n")
+        .trim_end()
+        .to_string()
+}
+
 #[cfg(test)]
 mod tests {
-    use super::ShellError;
+    use super::{fragment, one, table};
-    use super::ToMarkdown;
+    use nu_protocol::{row, Value};
 
     #[test]
-    fn examples_work_as_expected() -> Result<(), ShellError> {
+    fn render_h1() {
-        use crate::examples::test as test_examples;
+        let value = row! {"H1".into() => Value::from("Ecuador")};
 
-        Ok(test_examples(ToMarkdown {})?)
+        assert_eq!(fragment(&value, false), "# Ecuador\n");
+    }
+
+    #[test]
+    fn render_h2() {
+        let value = row! {"H2".into() => Value::from("Ecuador")};
+
+        assert_eq!(fragment(&value, false), "## Ecuador\n");
+    }
+
+    #[test]
+    fn render_h3() {
+        let value = row! {"H3".into() => Value::from("Ecuador")};
+
+        assert_eq!(fragment(&value, false), "### Ecuador\n");
+    }
+
+    #[test]
+    fn render_blockquote() {
+        let value = row! {"BLOCKQUOTE".into() => Value::from("Ecuador")};
+
+        assert_eq!(fragment(&value, false), "> Ecuador\n");
+    }
+
+    #[test]
+    fn render_table() {
+        let value = vec![
+            row! { "country".into() => Value::from("Ecuador")},
+            row! { "country".into() => Value::from("New Zealand")},
+            row! { "country".into() => Value::from("USA")},
+        ];
+
+        assert_eq!(
+            table(&value, false),
+            one(r#"
+            |country|
+            |-|
+            |Ecuador|
+            |New Zealand|
+            |USA|
+        "#)
+        );
+
+        assert_eq!(
+            table(&value, true),
+            one(r#"
+            | country     |
+            | ----------- |
+            | Ecuador     |
+            | New Zealand |
+            | USA         |
+        "#)
+        );
     }
 }

crates/nu-command/src/examples.rs

@@ -16,7 +16,7 @@ use nu_protocol::{ShellTypeName, Value};
 use nu_source::AnchorLocation;
 
 use crate::commands::{
-    BuildString, Each, Echo, First, Get, Keep, Last, Let, Nth, StrCollect, Wrap,
+    Append, BuildString, Each, Echo, First, Get, Keep, Last, Let, Nth, Select, StrCollect, Wrap,
 };
 use nu_engine::{run_block, whole_stream_command, Command, EvaluationContext, WholeStreamCommand};
 use nu_stream::InputStream;
@@ -32,6 +32,7 @@ pub fn test_examples(cmd: Command) -> Result<(), ShellError> {
         // Command Doubles
         whole_stream_command(DoubleLs {}),
         // Minimal restricted commands to aid in testing
+        whole_stream_command(Append {}),
         whole_stream_command(Echo {}),
         whole_stream_command(BuildString {}),
         whole_stream_command(First {}),
@@ -41,6 +42,7 @@ pub fn test_examples(cmd: Command) -> Result<(), ShellError> {
         whole_stream_command(Last {}),
         whole_stream_command(Nth {}),
         whole_stream_command(Let {}),
+        whole_stream_command(Select),
         whole_stream_command(StrCollect),
         whole_stream_command(Wrap),
         cmd,
@@ -100,6 +102,7 @@ pub fn test(cmd: impl WholeStreamCommand + 'static) -> Result<(), ShellError> {
         whole_stream_command(Each {}),
         whole_stream_command(Let {}),
         whole_stream_command(cmd),
+        whole_stream_command(Select),
         whole_stream_command(StrCollect),
         whole_stream_command(Wrap),
     ]);
@@ -153,6 +156,7 @@ pub fn test_anchors(cmd: Command) -> Result<(), ShellError> {
         whole_stream_command(StubOpen {}),
         whole_stream_command(DoubleEcho {}),
         whole_stream_command(DoubleLs {}),
+        whole_stream_command(Append {}),
         whole_stream_command(BuildString {}),
         whole_stream_command(First {}),
         whole_stream_command(Get {}),
@@ -161,6 +165,7 @@ pub fn test_anchors(cmd: Command) -> Result<(), ShellError> {
         whole_stream_command(Last {}),
         whole_stream_command(Nth {}),
         whole_stream_command(Let {}),
+        whole_stream_command(Select),
         whole_stream_command(StrCollect),
         whole_stream_command(Wrap),
         cmd,
@@ -172,6 +177,8 @@ pub fn test_anchors(cmd: Command) -> Result<(), ShellError> {
         let mut ctx = base_context.clone();
 
         let block = parse_line(&pipeline_with_anchor, &ctx)?;
+
+        if let Some(_) = &sample_pipeline.result {
             let result = block_on(evaluate_block(block, &mut ctx))?;
 
             ctx.with_errors(|reasons| reasons.iter().cloned().take(1).next())
@@ -190,6 +197,7 @@ pub fn test_anchors(cmd: Command) -> Result<(), ShellError> {
                 }
             }
         }
+    }
 
     Ok(())
 }

crates/nu-command/src/examples/sample.rs

@@ -7,7 +7,7 @@ pub mod ls {
     pub fn file_listing() -> Vec<Value> {
         vec![
             row! {
-                   "name".to_string() => string("Andrés.txt"),
+                   "name".to_string() => string("Andres.txt"),
                    "type".to_string() =>       string("File"),
                "chickens".to_string() =>              int(10),
                "modified".to_string() =>   date("2019-07-23")
@@ -19,7 +19,7 @@ pub mod ls {
                "modified".to_string() =>   date("2019-07-23")
             },
             row! {
-                   "name".to_string() =>  string("Andrés.txt"),
+                   "name".to_string() =>  string("Darren.txt"),
                    "type".to_string() =>        string("File"),
                "chickens".to_string() =>               int(20),
                "modified".to_string() =>    date("2019-09-24")

crates/nu-command/tests/format_conversions/markdown.rs

@@ -5,7 +5,7 @@ fn md_empty() {
     let actual = nu!(
         cwd: ".", pipeline(
         r#"
-            echo "{}" | from json | to md
+            echo [[]; []] | from json | to md
         "#
     ));
 
@@ -53,7 +53,7 @@ fn md_table() {
     let actual = nu!(
         cwd: ".", pipeline(
         r#"
-            echo '{"name": "jason"}' | from json | to md
+            echo [[name]; [jason]] | to md
         "#
     ));
 
@@ -65,9 +65,34 @@ fn md_table_pretty() {
     let actual = nu!(
         cwd: ".", pipeline(
         r#"
-            echo '{"name": "joseph"}' | from json | to md -p
+            echo [[name]; [joseph]] | to md -p
         "#
     ));
 
     assert_eq!(actual.out, "| name   || ------ || joseph |");
 }
+
+#[test]
+fn md_combined() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+            def title [] {
+                echo [[H1]; ["Nu top meals"]]
+            };
+
+            def meals [] {
+                echo [[dish]; [Arepa] [Taco] [Pizza]]
+            };
+
+            title
+            | append $(meals)
+            | to md --per-element --pretty
+        "#
+    ));
+
+    assert_eq!(
+        actual.out,
+        "# Nu top meals| dish  || ----- || Arepa || Taco  || Pizza |"
+    );
+}

crates/nu-protocol/src/value.rs

@@ -920,6 +920,67 @@ impl DateTimeExt for DateTime<FixedOffset> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use indexmap::indexmap;
+
+    #[test]
+    fn test_merge_descriptors() {
+        let value = vec![
+            UntaggedValue::row(indexmap! {
+                "h1".into() => Value::from("Ecuador")
+            })
+            .into_untagged_value(),
+            UntaggedValue::row(indexmap! {
+                "h2".into() => Value::from("Ecuador")
+            })
+            .into_untagged_value(),
+            UntaggedValue::row(indexmap! {
+                "h3".into() => Value::from("Ecuador")
+            })
+            .into_untagged_value(),
+            UntaggedValue::row(indexmap! {
+                "h1".into() => Value::from("Ecuador"),
+                "h4".into() => Value::from("Ecuador"),
+            })
+            .into_untagged_value(),
+        ];
+
+        assert_eq!(
+            merge_descriptors(&value),
+            vec![
+                String::from("h1"),
+                String::from("h2"),
+                String::from("h3"),
+                String::from("h4")
+            ]
+        );
+    }
+
+    #[test]
+    fn test_data_descriptors() {
+        let value = vec![
+            UntaggedValue::row(indexmap! {
+                "h1".into() => Value::from("Ecuador")
+            }),
+            UntaggedValue::row(indexmap! {
+                "h2".into() => Value::from("Ecuador")
+            }),
+            UntaggedValue::row(indexmap! {
+                "h3".into() => Value::from("Ecuador")
+            }),
+            UntaggedValue::row(indexmap! {
+                "h1".into() => Value::from("Ecuador"),
+                "h4".into() => Value::from("Ecuador"),
+            }),
+        ];
+
+        assert_eq!(
+            value
+                .iter()
+                .map(|v| v.data_descriptors().len())
+                .collect::<Vec<_>>(),
+            vec![1, 1, 1, 2]
+        );
+    }
 
     #[test]
     fn test_decimal_from_float() {