Add flag for case-insensitive sort-by (#2225)

* Add flag for case-insensitive sort-by

* Fix test names

* Fix documentation comments

crates/nu-cli/src/commands/math/median.rs

@@ -73,7 +73,7 @@ pub fn median(values: &[Value], name: &Tag) -> Result<Value, ShellError> {
         sorted.push(item.clone());
     }
 
-    crate::commands::sort_by::sort(&mut sorted, &[], name)?;
+    crate::commands::sort_by::sort(&mut sorted, &[], name, false)?;
 
     match take {
         Pick::Median => {

crates/nu-cli/src/commands/math/mode.rs

@@ -77,7 +77,7 @@ pub fn mode(values: &[Value], name: &Tag) -> Result<Value, ShellError> {
         }
     }
 
-    crate::commands::sort_by::sort(&mut modes, &[], name)?;
+    crate::commands::sort_by::sort(&mut modes, &[], name, false)?;
     Ok(UntaggedValue::Table(modes).into_value(name))
 }
 

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

@@ -11,6 +11,7 @@ pub struct SortBy;
 #[derive(Deserialize)]
 pub struct SortByArgs {
     rest: Vec<Tagged<String>>,
+    insensitive: bool,
 }
 
 #[async_trait]
@@ -20,7 +21,13 @@ impl WholeStreamCommand for SortBy {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("sort-by").rest(SyntaxShape::String, "the column(s) to sort by")
+        Signature::build("sort-by")
+            .switch(
+                "insensitive",
+                "Sort string-based columns case insensitively",
+                Some('i'),
+            )
+            .rest(SyntaxShape::String, "the column(s) to sort by")
     }
 
     fn usage(&self) -> &str {
@@ -57,6 +64,24 @@ impl WholeStreamCommand for SortBy {
                 example: "ls | sort-by type size",
                 result: None,
             },
+            Example {
+                description: "Sort strings (case sensitive)",
+                example: "echo [airplane Truck Car] | sort-by",
+                result: Some(vec![
+                    UntaggedValue::string("Car").into(),
+                    UntaggedValue::string("Truck").into(),
+                    UntaggedValue::string("airplane").into(),
+                ]),
+            },
+            Example {
+                description: "Sort strings (case insensitive)",
+                example: "echo [airplane Truck Car] | sort-by -i",
+                result: Some(vec![
+                    UntaggedValue::string("airplane").into(),
+                    UntaggedValue::string("Car").into(),
+                    UntaggedValue::string("Truck").into(),
+                ]),
+            },
         ]
     }
 }
@@ -68,10 +93,10 @@ async fn sort_by(
     let registry = registry.clone();
     let tag = args.call_info.name_tag.clone();
 
-    let (SortByArgs { rest }, mut input) = args.process(&registry).await?;
+    let (SortByArgs { rest, insensitive }, mut input) = args.process(&registry).await?;
     let mut vec = input.drain_vec().await;
 
-    sort(&mut vec, &rest, &tag)?;
+    sort(&mut vec, &rest, &tag, insensitive)?;
 
     Ok(futures::stream::iter(vec.into_iter()).to_output_stream())
 }
@@ -80,6 +105,7 @@ pub fn sort(
     vec: &mut [Value],
     keys: &[Tagged<String>],
     tag: impl Into<Tag>,
+    insensitive: bool,
 ) -> Result<(), ShellError> {
     let tag = tag.into();
 
@@ -107,12 +133,38 @@ pub fn sort(
             value: UntaggedValue::Primitive(_),
             ..
         } => {
-            vec.sort_by(|a, b| coerce_compare(a, b).expect("Unimplemented BUG: What about primitives that don't have an order defined?").compare());
+            let should_sort_case_insensitively = insensitive && vec.iter().all(|x| x.is_string());
+
+            vec.sort_by(|a, b| {
+                if should_sort_case_insensitively {
+                    let lowercase_a_string = a.expect_string().to_ascii_lowercase();
+                    let lowercase_b_string = b.expect_string().to_ascii_lowercase();
+
+                    lowercase_a_string.cmp(&lowercase_b_string)
+                } else {
+                    coerce_compare(a, b).expect("Unimplemented BUG: What about primitives that don't have an order defined?").compare()
+                }
+            });
         }
         _ => {
             let calc_key = |item: &Value| {
                 keys.iter()
-                    .map(|f| get_data_by_key(item, f.borrow_spanned()))
+                    .map(|f| {
+                        let mut value_option = get_data_by_key(item, f.borrow_spanned());
+
+                        if insensitive {
+                            if let Some(value) = &value_option {
+                                if let Ok(string_value) = value.as_string() {
+                                    value_option = Some(
+                                        UntaggedValue::string(string_value.to_ascii_lowercase())
+                                            .into_value(value.tag.clone()),
+                                    )
+                                }
+                            }
+                        }
+
+                        value_option
+                    })
                     .collect::<Vec<Option<Value>>>()
             };
             vec.sort_by_cached_key(calc_key);

crates/nu-cli/tests/commands/sort_by.rs

@@ -62,3 +62,71 @@ fn sort_primitive_values() {
 
     assert_eq!(actual.out, "authors = [\"The Nu Project Contributors\"]");
 }
+
+#[test]
+fn ls_sort_by_name_sensitive() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample-ls-output.json
+            | sort-by name
+            | select name
+            | to json
+        "#
+    ));
+
+    let json_output = r#"[{"name":"B.txt"},{"name":"C"},{"name":"a.txt"}]"#;
+
+    assert_eq!(actual.out, json_output);
+}
+
+#[test]
+fn ls_sort_by_name_insensitive() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample-ls-output.json
+            | sort-by -i name
+            | select name
+            | to json
+        "#
+    ));
+
+    let json_output = r#"[{"name":"a.txt"},{"name":"B.txt"},{"name":"C"}]"#;
+
+    assert_eq!(actual.out, json_output);
+}
+
+#[test]
+fn ls_sort_by_type_name_sensitive() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample-ls-output.json
+            | sort-by type name
+            | select name type
+            | to json
+        "#
+    ));
+
+    let json_output = r#"[{"name":"C","type":"Dir"},{"name":"B.txt","type":"File"},{"name":"a.txt","type":"File"}]"#;
+
+    assert_eq!(actual.out, json_output);
+}
+
+#[test]
+fn ls_sort_by_type_name_insensitive() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample-ls-output.json
+            | sort-by -i type name
+            | select name type
+            | to json
+        "#
+    ));
+
+    let json_output = r#"[{"name":"C","type":"Dir"},{"name":"a.txt","type":"File"},{"name":"B.txt","type":"File"}]"#;
+
+    assert_eq!(actual.out, json_output);
+}

crates/nu-protocol/src/value.rs

@@ -85,6 +85,11 @@ impl UntaggedValue {
         matches!(self, UntaggedValue::Table(_))
     }
 
+    /// Returns true if this value represents a string
+    pub fn is_string(&self) -> bool {
+        matches!(self, UntaggedValue::Primitive(Primitive::String(_)))
+    }
+
     /// Returns true if the value represents something other than Nothing
     pub fn is_some(&self) -> bool {
         !self.is_none()

docs/commands/sort-by.md

@@ -5,6 +5,10 @@ The `sort-by` command sorts the table being displayed in the terminal by a chose
 
 `sort-by` takes multiple arguments (being the names of columns) sorting by each argument in order.
 
+## Flags
+
+* `-i`, `--insensitive`: Sort string-based columns case insensitively
+
 ## Examples
 
 ```shell
@@ -53,3 +57,67 @@ The `sort-by` command sorts the table being displayed in the terminal by a chose
  7 │ az   │ File │          │  18 B  │ 5 minutes ago  │ 5 minutes ago
 ━━━┷━━━━━━┷━━━━━━┷━━━━━━━━━━┷━━━━━━━━┷━━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━
 ```
+
+Within the Nushell repository...
+
+```shell
+> ls | sort-by --insensitive name
+────┬────────────────────┬──────┬──────────┬──────────────
+ #  │ name               │ type │ size     │ modified
+────┼────────────────────┼──────┼──────────┼──────────────
+  0 │ assets             │ Dir  │    128 B │ 6 months ago
+  1 │ build.rs           │ File │     78 B │ 5 months ago
+  2 │ Cargo.lock         │ File │ 118.3 KB │ 1 hour ago
+  3 │ Cargo.toml         │ File │   5.5 KB │ 1 hour ago
+  4 │ CODE_OF_CONDUCT.md │ File │   3.4 KB │ 1 hour ago
+  5 │ CONTRIBUTING.md    │ File │   1.3 KB │ 1 hour ago
+  6 │ crates             │ Dir  │    832 B │ 1 hour ago
+  7 │ debian             │ Dir  │    352 B │ 6 months ago
+  8 │ docker             │ Dir  │    288 B │ 4 months ago
+  9 │ docs               │ Dir  │    192 B │ 1 hour ago
+ 10 │ features.toml      │ File │    632 B │ 5 months ago
+ 11 │ images             │ Dir  │    160 B │ 6 months ago
+ 12 │ LICENSE            │ File │   1.1 KB │ 4 months ago
+ 13 │ Makefile.toml      │ File │    449 B │ 6 months ago
+ 14 │ README.build.txt   │ File │    192 B │ 1 hour ago
+ 15 │ README.md          │ File │  16.0 KB │ 1 hour ago
+ 16 │ rustfmt.toml       │ File │     16 B │ 6 months ago
+ 17 │ src                │ Dir  │    128 B │ 1 week ago
+ 18 │ target             │ Dir  │    160 B │ 1 day ago
+ 19 │ tests              │ Dir  │    192 B │ 4 months ago
+ 20 │ TODO.md            │ File │      0 B │ 1 week ago
+ 21 │ wix                │ Dir  │    128 B │ 1 hour ago
+────┴────────────────────┴──────┴──────────┴──────────────
+```
+
+Within the Nushell repository...
+
+```shell
+> ls | sort-by --insensitive type name
+────┬────────────────────┬──────┬──────────┬──────────────
+ #  │ name               │ type │ size     │ modified
+────┼────────────────────┼──────┼──────────┼──────────────
+  0 │ assets             │ Dir  │    128 B │ 6 months ago
+  1 │ crates             │ Dir  │    832 B │ 1 hour ago
+  2 │ debian             │ Dir  │    352 B │ 6 months ago
+  3 │ docker             │ Dir  │    288 B │ 4 months ago
+  4 │ docs               │ Dir  │    192 B │ 1 hour ago
+  5 │ images             │ Dir  │    160 B │ 6 months ago
+  6 │ src                │ Dir  │    128 B │ 1 week ago
+  7 │ target             │ Dir  │    160 B │ 1 day ago
+  8 │ tests              │ Dir  │    192 B │ 4 months ago
+  9 │ wix                │ Dir  │    128 B │ 1 hour ago
+ 10 │ build.rs           │ File │     78 B │ 5 months ago
+ 11 │ Cargo.lock         │ File │ 118.3 KB │ 1 hour ago
+ 12 │ Cargo.toml         │ File │   5.5 KB │ 1 hour ago
+ 13 │ CODE_OF_CONDUCT.md │ File │   3.4 KB │ 1 hour ago
+ 14 │ CONTRIBUTING.md    │ File │   1.3 KB │ 1 hour ago
+ 15 │ features.toml      │ File │    632 B │ 5 months ago
+ 16 │ LICENSE            │ File │   1.1 KB │ 4 months ago
+ 17 │ Makefile.toml      │ File │    449 B │ 6 months ago
+ 18 │ README.build.txt   │ File │    192 B │ 1 hour ago
+ 19 │ README.md          │ File │  16.0 KB │ 1 hour ago
+ 20 │ rustfmt.toml       │ File │     16 B │ 6 months ago
+ 21 │ TODO.md            │ File │      0 B │ 1 week ago
+────┴────────────────────┴──────┴──────────┴──────────────
+```

tests/fixtures/formats/sample-ls-output.json

@@ -0,0 +1 @@
+[{"name":"a.txt","type":"File","size":3444,"modified":"2020-07-1918:26:30.560716967UTC"},{"name":"B.txt","type":"File","size":1341,"modified":"2020-07-1918:26:30.561021953UTC"},{"name":"C","type":"Dir","size":118253,"modified":"2020-07-1918:26:30.562092480UTC"}]