feat(rome_json_formatter): JSON Formatting object rome#2570

crates/rome_formatter/src/lib.rs

@@ -37,6 +37,7 @@ pub mod printed_tokens;
 pub mod printer;
 mod source_map;
 pub mod trivia;
+pub mod utils;
 mod verbatim;
 
 use crate::formatter::Formatter;

crates/rome_formatter/src/utils.rs

@@ -0,0 +1,13 @@
+use rome_rowan::{Language, SyntaxNode};
+
+/// Returns true if this node contains newlines in trivias.
+pub fn node_has_leading_newline<L: Language>(node: &SyntaxNode<L>) -> bool {
+    if let Some(leading_trivia) = node.first_leading_trivia() {
+        for piece in leading_trivia.pieces() {
+            if piece.is_newline() {
+                return true;
+            }
+        }
+    }
+    false
+}

crates/rome_js_formatter/src/js/module/export_named_from_clause.rs

@@ -1,5 +1,6 @@
 use crate::prelude::*;
-use crate::utils::{node_has_leading_newline, FormatStatementSemicolon};
+use crate::utils::FormatStatementSemicolon;
+use rome_formatter::utils::node_has_leading_newline;
 use rome_formatter::write;
 
 use rome_js_syntax::JsExportNamedFromClause;

crates/rome_js_formatter/src/utils/mod.rs

@@ -33,10 +33,10 @@ pub(crate) use conditional::{AnyJsConditional, ConditionalJsxChain};
 pub(crate) use object_like::JsObjectLike;
 pub(crate) use object_pattern_like::JsObjectPatternLike;
 use rome_formatter::{format_args, write, Buffer};
+use rome_js_syntax::JsSyntaxToken;
 use rome_js_syntax::{
     AnyJsExpression, AnyJsStatement, JsCallExpression, JsInitializerClause, JsLanguage, Modifiers,
 };
-use rome_js_syntax::{JsSyntaxNode, JsSyntaxToken};
 use rome_rowan::{AstNode, AstNodeList};
 pub(crate) use string_utils::*;
 pub(crate) use typescript::{
@@ -142,18 +142,6 @@ impl Format<JsFormatContext> for FormatInterpreterToken<'_> {
     }
 }
 
-/// Returns true if this node contains newlines in trivias.
-pub(crate) fn node_has_leading_newline(node: &JsSyntaxNode) -> bool {
-    if let Some(leading_trivia) = node.first_leading_trivia() {
-        for piece in leading_trivia.pieces() {
-            if piece.is_newline() {
-                return true;
-            }
-        }
-    }
-    false
-}
-
 /// Formats the body of a statement where it can either be a single statement, an empty statement,
 /// or a block statement.
 pub(crate) struct FormatStatementBody<'a> {

crates/rome_js_formatter/src/utils/object_like.rs

@@ -1,6 +1,6 @@
 use crate::prelude::*;
-use crate::utils::node_has_leading_newline;
 use crate::JsFormatContext;
+use rome_formatter::utils::node_has_leading_newline;
 use rome_formatter::write;
 use rome_formatter::{Format, FormatResult};
 use rome_js_syntax::{JsObjectExpression, JsSyntaxToken, TsObjectType};

crates/rome_json_formatter/src/json/auxiliary/member.rs

@@ -1,12 +1,24 @@
 use crate::prelude::*;
+use rome_formatter::write;
 use rome_json_syntax::JsonMember;
-use rome_rowan::AstNode;
 
 #[derive(Debug, Clone, Default)]
 pub(crate) struct FormatJsonMember;
 
 impl FormatNodeRule<JsonMember> for FormatJsonMember {
     fn fmt_fields(&self, node: &JsonMember, f: &mut JsonFormatter) -> FormatResult<()> {
-        format_verbatim_node(node.syntax()).fmt(f)
+        let content = format_with(move |f| {
+            write!(
+                f,
+                [
+                    group(&node.name().format()),
+                    node.colon_token().format(),
+                    space(),
+                    node.value().format()
+                ]
+            )
+        });
+
+        write!(f, [group(&content)])
     }
 }

crates/rome_json_formatter/src/json/lists/member_list.rs

@@ -1,12 +1,20 @@
 use crate::prelude::*;
+use crate::separated::FormatAstSeparatedListExtension;
 use rome_json_syntax::JsonMemberList;
+use rome_rowan::{AstNode, AstSeparatedList};
 
 #[derive(Debug, Clone, Default)]
 pub(crate) struct FormatJsonMemberList;
 
 impl FormatRule<JsonMemberList> for FormatJsonMemberList {
     type Context = JsonFormatContext;
     fn fmt(&self, node: &JsonMemberList, f: &mut JsonFormatter) -> FormatResult<()> {
-        format_verbatim_node(node.syntax()).fmt(f)
+        let mut join = f.join_nodes_with_soft_line();
+
+        for (element, formatted) in node.elements().zip(node.format_separated(",")) {
+            join.entry(element.node()?.syntax(), &formatted);
+        }
+
+        join.finish()
     }
 }

crates/rome_json_formatter/src/json/value/object_value.rs

@@ -1,4 +1,6 @@
 use crate::prelude::*;
+use rome_formatter::utils::node_has_leading_newline;
+use rome_formatter::write;
 use rome_json_syntax::JsonObjectValue;
 use rome_rowan::AstNode;
 
@@ -7,6 +9,18 @@ pub(crate) struct FormatJsonObjectValue;
 
 impl FormatNodeRule<JsonObjectValue> for FormatJsonObjectValue {
     fn fmt_fields(&self, node: &JsonObjectValue, f: &mut JsonFormatter) -> FormatResult<()> {
-        format_verbatim_node(node.syntax()).fmt(f)
+        write!(f, [node.l_curly_token().format(),])?;
+
+        let should_expand = node_has_leading_newline(node.json_member_list().syntax());
+
+        write!(
+            f,
+            [group(&soft_space_or_block_indent(
+                &node.json_member_list().format()
+            ))
+            .should_expand(should_expand)]
+        )?;
+
+        write!(f, [node.r_curly_token().format()])
     }
 }

crates/rome_json_formatter/src/lib.rs

@@ -3,6 +3,7 @@ mod cst;
 mod generated;
 mod json;
 mod prelude;
+mod separated;
 
 pub(crate) use crate::context::JsonFormatContext;
 use crate::context::JsonFormatOptions;
@@ -170,21 +171,10 @@ mod tests {
 "#;
         let parse = parse_json(src, FileId::zero());
         let options = JsonFormatOptions::default();
-        let result = format_node(options, &parse.syntax())
-            .unwrap()
-            .print()
-            .unwrap();
-
+        let formatted = format_node(options, &parse.syntax()).unwrap();
         assert_eq!(
-            result.as_code(),
-            r#"{
-    "a": 5,
-    "b": [1, 2, 3, 4],
-    "c": null,
-    "d": true,
-    "e": false
-}
-"#
+            formatted.print().unwrap().as_code(),
+            "{\n\t\"a\": 5,\n\t\"b\": [1, 2, 3, 4],\n\t\"c\": null,\n\t\"d\": true,\n\t\"e\": false\n}\n"
         );
     }
 }

crates/rome_json_formatter/src/separated.rs

@@ -0,0 +1,159 @@
+use crate::prelude::*;
+use crate::AsFormat;
+use rome_formatter::{write, GroupId};
+use rome_json_syntax::JsonLanguage;
+use rome_rowan::{
+    AstNode, AstSeparatedElement, AstSeparatedList, AstSeparatedListElementsIterator, Language,
+    SyntaxResult,
+};
+use std::iter::FusedIterator;
+
+/// Formats a single element inside of a separated list.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct FormatSeparatedElement<L: Language, N> {
+    element: AstSeparatedElement<L, N>,
+    is_last: bool,
+    /// The separator to write if the element has no separator yet.
+    separator: &'static str,
+    options: FormatSeparatedOptions,
+}
+
+impl<L: Language, N: AstNode<Language = L>> FormatSeparatedElement<L, N> {
+    /// Returns the node belonging to the element.
+    #[allow(unused)]
+    pub fn node(&self) -> SyntaxResult<&N> {
+        self.element.node()
+    }
+}
+
+impl<N> Format<JsonFormatContext> for FormatSeparatedElement<JsonLanguage, N>
+where
+    N: AstNode<Language = JsonLanguage> + AsFormat<JsonFormatContext>,
+{
+    fn fmt(&self, f: &mut Formatter<JsonFormatContext>) -> FormatResult<()> {
+        let node = self.element.node()?;
+        let separator = self.element.trailing_separator()?;
+
+        if !self.options.nodes_grouped {
+            node.format().fmt(f)?;
+        } else {
+            group(&node.format()).fmt(f)?;
+        }
+
+        // Reuse the existing trailing separator or create it if it wasn't in the
+        // input source. Only print the last trailing token if the outer group breaks
+        if let Some(separator) = separator {
+            if self.is_last {
+                return Err(FormatError::SyntaxError);
+            } else {
+                write!(f, [separator.format()])?;
+            }
+        } else if self.is_last {
+            /* no op */
+        } else {
+            unreachable!(
+                "This is a syntax error, separator must be present between every two elements"
+            );
+        };
+
+        Ok(())
+    }
+}
+
+/// Iterator for formatting separated elements. Prints the separator between each element and
+/// inserts a trailing separator if necessary
+pub struct FormatSeparatedIter<I, Language, Node>
+where
+    Language: rome_rowan::Language,
+{
+    next: Option<AstSeparatedElement<Language, Node>>,
+    inner: I,
+    separator: &'static str,
+    options: FormatSeparatedOptions,
+}
+
+impl<I, L, Node> FormatSeparatedIter<I, L, Node>
+where
+    L: Language,
+{
+    fn new(inner: I, separator: &'static str) -> Self {
+        Self {
+            inner,
+            separator,
+            next: None,
+            options: FormatSeparatedOptions::default(),
+        }
+    }
+
+    /// Wraps every node inside of a group
+    #[allow(unused)]
+    pub fn nodes_grouped(mut self) -> Self {
+        self.options.nodes_grouped = true;
+        self
+    }
+
+    #[allow(unused)]
+    pub fn with_group_id(mut self, group_id: Option<GroupId>) -> Self {
+        self.options.group_id = group_id;
+        self
+    }
+}
+
+impl<I, N> Iterator for FormatSeparatedIter<I, JsonLanguage, N>
+where
+    I: Iterator<Item = AstSeparatedElement<JsonLanguage, N>>,
+{
+    type Item = FormatSeparatedElement<JsonLanguage, N>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let element = self.next.take().or_else(|| self.inner.next())?;
+
+        self.next = self.inner.next();
+        let is_last = self.next.is_none();
+
+        Some(FormatSeparatedElement {
+            element,
+            is_last,
+            separator: self.separator,
+            options: self.options,
+        })
+    }
+}
+
+impl<I, N> FusedIterator for FormatSeparatedIter<I, JsonLanguage, N> where
+    I: Iterator<Item = AstSeparatedElement<JsonLanguage, N>> + FusedIterator
+{
+}
+
+impl<I, N> ExactSizeIterator for FormatSeparatedIter<I, JsonLanguage, N> where
+    I: Iterator<Item = AstSeparatedElement<JsonLanguage, N>> + ExactSizeIterator
+{
+}
+
+/// AST Separated list formatting extension methods
+pub trait FormatAstSeparatedListExtension: AstSeparatedList<Language = JsonLanguage> {
+    /// Prints a separated list of nodes
+    ///
+    /// Trailing separators will be reused from the original list or
+    /// created by calling the `separator_factory` function.
+    /// The last trailing separator in the list will only be printed
+    /// if the outer group breaks.
+    fn format_separated(
+        &self,
+        separator: &'static str,
+    ) -> FormatSeparatedIter<
+        AstSeparatedListElementsIterator<JsonLanguage, Self::Node>,
+        JsonLanguage,
+        Self::Node,
+    > {
+        FormatSeparatedIter::new(self.elements(), separator)
+    }
+}
+
+impl<T> FormatAstSeparatedListExtension for T where T: AstSeparatedList<Language = JsonLanguage> {}
+
+#[derive(Debug, Default, Copy, Clone, Eq, PartialEq)]
+pub struct FormatSeparatedOptions {
+    group_id: Option<GroupId>,
+    nodes_grouped: bool,
+}

crates/rome_json_formatter/tests/specs/json/object/complex.json

@@ -0,0 +1,7 @@
+{
+	"number": 1123123213123123123123122311231232131231231231231223,
+	"string": "some-long-long-long-long-long-long-long-string",
+	"array": [12312321, {"another-number": 12321321, "string": "some-string"}],
+	"object": {"array":  [123214123, "some-long-long-string", [12312312, "some-long-long-string"]]},
+	"null": null
+}