Add pretty flag to to md (#2640)

* First draft for adding a `pretty` flag to `to md`

* rustfmt

* Fix Clippy warnings

* rustfmt

* Using Clippy suggestion broken code, reverting and putting in a statement to ignore clippy warning

* Add test for `to md -p`

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

@@ -7,6 +7,11 @@ use nu_protocol::{ReturnSuccess, Signature, UntaggedValue, Value};
 
 pub struct ToMarkdown;
 
+#[derive(Deserialize)]
+pub struct ToMarkdownArgs {
+    pretty: bool,
+}
+
 #[async_trait]
 impl WholeStreamCommand for ToMarkdown {
     fn name(&self) -> &str {
@@ -14,7 +19,11 @@ impl WholeStreamCommand for ToMarkdown {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("to md")
+        Signature::build("to md").switch(
+            "pretty",
+            "Formats the Markdown table to vertically align items",
+            Some('p'),
+        )
     }
 
     fn usage(&self) -> &str {
@@ -28,27 +37,84 @@ impl WholeStreamCommand for ToMarkdown {
     ) -> Result<OutputStream, ShellError> {
         to_md(args, registry).await
     }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Outputs an unformatted md string representing the contents of ls",
+                example: "ls | to md",
+                result: None,
+            },
+            Example {
+                description: "Outputs a formatted md string representing the contents of ls",
+                example: "ls | to md -p",
+                result: None,
+            },
+        ]
+    }
 }
 
 async fn to_md(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     let registry = registry.clone();
-    let args = args.evaluate_once(&registry).await?;
+    let name_tag = args.call_info.name_tag.clone();
-    let name_tag = args.name_tag();
+    let (ToMarkdownArgs { pretty }, input) = args.process(&registry).await?;
-    let input: Vec<Value> = args.input.collect().await;
+    let input: Vec<Value> = input.collect().await;
     let headers = nu_protocol::merge_descriptors(&input);
     let mut output_string = String::new();
 
+    let mut column_length_vector: Vec<usize> = Vec::new();
+
+    if pretty {
+        if !headers.is_empty() && (headers.len() > 1 || headers[0] != "") {
+            for header in &headers {
+                let htmlescape_header_string = &htmlescape::encode_minimal(&header);
+                column_length_vector.push(htmlescape_header_string.len());
+            }
+        }
+
+        for row in &input {
+            if let UntaggedValue::Row(row) = row.value.clone() {
+                for i in 0..headers.len() {
+                    let data = row.get_data(&headers[i]);
+                    let new_column_length = format_leaf(data.borrow()).plain_string(100_000).len();
+
+                    if column_length_vector[i] < new_column_length {
+                        column_length_vector[i] = new_column_length;
+                    }
+                }
+            }
+        }
+    }
+
     if !headers.is_empty() && (headers.len() > 1 || headers[0] != "") {
         output_string.push_str("|");
-        for header in &headers {
+
-            output_string.push_str(&htmlescape::encode_minimal(&header));
+        for i in 0..headers.len() {
+            let htmlescape_string = htmlescape::encode_minimal(&headers[i]);
+            let final_string = if pretty {
+                get_padded_string(htmlescape_string, column_length_vector[i], ' ')
+            } else {
+                htmlescape_string
+            };
+
+            output_string.push_str(&final_string);
             output_string.push_str("|");
         }
+
         output_string.push_str("\n|");
-        for _ in &headers {
+
-            output_string.push_str("-");
+        #[allow(clippy::needless_range_loop)]
+        for i in 0..headers.len() {
+            let final_string = if pretty {
+                "-".repeat(column_length_vector[i])
+            } else {
+                String::from("-")
+            };
+
+            output_string.push_str(final_string.as_str());
             output_string.push_str("|");
         }
+
         output_string.push_str("\n");
     }
 
@@ -56,11 +122,20 @@ async fn to_md(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputSt
         match row.value {
             UntaggedValue::Row(row) => {
                 output_string.push_str("|");
-                for header in &headers {
+
-                    let data = row.get_data(header);
+                for i in 0..headers.len() {
-                    output_string.push_str(&format_leaf(data.borrow()).plain_string(100_000));
+                    let data = row.get_data(&headers[i]);
+                    let leaf_string = format_leaf(data.borrow()).plain_string(100_000);
+                    let final_string = if pretty {
+                        get_padded_string(leaf_string, column_length_vector[i], ' ')
+                    } else {
+                        leaf_string
+                    };
+
+                    output_string.push_str(&final_string);
                     output_string.push_str("|");
                 }
+
                 output_string.push_str("\n");
             }
             p => {
@@ -77,6 +152,11 @@ async fn to_md(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputSt
     )))
 }
 
+fn get_padded_string(text: String, desired_length: usize, character: char) -> String {
+    let padding_length = desired_length - text.len();
+    return format!("{}{}", text, character.to_string().repeat(padding_length));
+}
+
 #[cfg(test)]
 mod tests {
     use super::ShellError;

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

@@ -23,3 +23,15 @@ fn out_md_table() {
 
     assert_eq!(actual.out, "|name||-||jason|");
 }
+
+#[test]
+fn out_md_table_pretty() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+            echo '{"name": "joseph"}' | from json | to md -p
+        "#
+    ));
+
+    assert_eq!(actual.out, "|name  ||------||joseph|");
+}

docs/commands/to-md.md

@@ -0,0 +1,67 @@
+# to md
+
+Convert table into simple Markdown.
+
+## Flags
+
+* `-p`, `--pretty`: Formats the Markdown table to vertically align items
+
+## Example
+
+```shell
+> ls | to md
+|name|type|size|modified|
+|-|-|-|-|
+|CODE_OF_CONDUCT.md|File|3.4 KB|2 months ago|
+|CONTRIBUTING.md|File|1.4 KB|1 month ago|
+|Cargo.lock|File|144.4 KB|2 days ago|
+|Cargo.toml|File|6.0 KB|2 days ago|
+|LICENSE|File|1.1 KB|2 months ago|
+|Makefile.toml|File|449 B|2 months ago|
+|README.build.txt|File|192 B|2 months ago|
+|README.md|File|15.9 KB|1 month ago|
+|TODO.md|File|0 B|2 months ago|
+|crates|Dir|896 B|2 days ago|
+|debian|Dir|352 B|2 months ago|
+|docker|Dir|288 B|1 month ago|
+|docs|Dir|256 B|1 month ago|
+|features.toml|File|632 B|2 months ago|
+|images|Dir|160 B|2 months ago|
+|pkg_mgrs|Dir|96 B|1 month ago|
+|rustfmt.toml|File|16 B|9 months ago|
+|samples|Dir|96 B|1 month ago|
+|src|Dir|128 B|2 days ago|
+|target|Dir|160 B|1 month ago|
+|tests|Dir|192 B|2 months ago|
+|wix|Dir|128 B|23 hours ago|
+```
+
+If we provide the `-p` flag, we can obtain a formatted version of the Markdown table
+
+```shell
+> ls | to md  -p
+|name              |type|size    |modified    |
+|------------------|----|--------|------------|
+|CODE_OF_CONDUCT.md|File|3.4 KB  |2 months ago|
+|CONTRIBUTING.md   |File|1.4 KB  |1 month ago |
+|Cargo.lock        |File|144.4 KB|2 days ago  |
+|Cargo.toml        |File|6.0 KB  |2 days ago  |
+|LICENSE           |File|1.1 KB  |2 months ago|
+|Makefile.toml     |File|449 B   |2 months ago|
+|README.build.txt  |File|192 B   |2 months ago|
+|README.md         |File|15.9 KB |1 month ago |
+|TODO.md           |File|0 B     |2 months ago|
+|crates            |Dir |896 B   |2 days ago  |
+|debian            |Dir |352 B   |2 months ago|
+|docker            |Dir |288 B   |1 month ago |
+|docs              |Dir |256 B   |1 month ago |
+|features.toml     |File|632 B   |2 months ago|
+|images            |Dir |160 B   |2 months ago|
+|pkg_mgrs          |Dir |96 B    |1 month ago |
+|rustfmt.toml      |File|16 B    |9 months ago|
+|samples           |Dir |96 B    |1 month ago |
+|src               |Dir |128 B   |2 days ago  |
+|target            |Dir |160 B   |1 month ago |
+|tests             |Dir |192 B   |2 months ago|
+|wix               |Dir |128 B   |23 hours ago|
+```

docs/commands/to.md

@@ -8,7 +8,7 @@ Converts table data into a string or binary. The target format is specified as a
 * [to csv](to-csv.md)
 * to html
 * [to json](to-json.md)
-* to md
+* [to md](to-md.md)
 * to sqlite
 * [to toml](to-toml.md)
 * [to tsv](to-tsv.md)