sdl-encoder: fix description encodings (#742)

This commit introduces `Description` helper to encode top-level, field-level and input-level descriptions. This helps unify some of the description logic we've had across multiple files.

This commit also checks whether a description string is a block string character or a string character which then determines whether description needs to be multilined.

Fixes #728.

Co-authored-by: Avery Harnish <avery@apollographql.com>

crates/rover-client/src/operations/graph/introspect/schema.rs

@@ -531,9 +531,13 @@ mod tests {
         type Species implements Node {
           """The name of this species."""
           name: String
-          """The classification of this species, such as "mammal" or "reptile"."""
+          """
+          The classification of this species, such as "mammal" or "reptile".
+          """
           classification: String
-          """The designation of this species, such as "sentient"."""
+          """
+          The designation of this species, such as "sentient".
+          """
           designation: String
           """The average height of this species in centimeters."""
           averageHeight: Float
@@ -750,7 +754,9 @@ mod tests {
         }
         """A single transport craft that has hyperdrive capability."""
         type Starship implements Node {
-          """The name of this starship. The common name, such as "Death Star"."""
+          """
+          The name of this starship. The common name, such as "Death Star".
+          """
           name: String
           """
           The model or official name of this starship. Such as "T-65 X-wing" or "DS-1
@@ -905,7 +911,9 @@ mod tests {
         Transport".
           """
           model: String
-          """The class of this vehicle, such as "Wheeled" or "Repulsorcraft"."""
+          """
+          The class of this vehicle, such as "Wheeled" or "Repulsorcraft".
+          """
           vehicleClass: String
           """The manufacturers of this vehicle."""
           manufacturers: [String]

crates/sdl-encoder/src/description.rs

@@ -0,0 +1,135 @@
+use std::fmt::{self, Display};
+
+#[derive(Debug, PartialEq, Clone)]
+/// Convenience enum to create a Description. Can be a `Top` level, a `Field`
+/// level or an `Input` level. The variants are distinguished by the way they
+/// get displayed, e.g. number of leading spaces.
+pub enum Description {
+    /// Top-level description.
+    Top {
+        /// Description.
+        source: Option<String>,
+    },
+    /// Field-level description.
+    /// This description gets additional leading spaces.
+    Field {
+        /// Description.
+        source: Option<String>,
+    },
+    /// Input-level description.
+    /// This description get an additional space at the end.
+    Input {
+        /// Description.
+        source: Option<String>,
+    },
+}
+
+impl Display for Description {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Description::Top { source } => {
+                if let Some(description) = source {
+                    if is_block_string_character(description) {
+                        writeln!(f, "\"\"\"\n{}\n\"\"\"", description)?
+                    } else {
+                        writeln!(f, "\"\"\"{}\"\"\"", description)?
+                    }
+                }
+            }
+            Description::Field { source } => {
+                if let Some(description) = source {
+                    if is_block_string_character(description) {
+                        writeln!(f, "  \"\"\"\n  {}\n  \"\"\"", description)?
+                    } else {
+                        writeln!(f, "  \"\"\"{}\"\"\"", description)?
+                    }
+                }
+            }
+            Description::Input { source } => {
+                if let Some(description) = source {
+                    if is_block_string_character(description) {
+                        write!(f, "\"\"\"\n{}\n\"\"\" ", description)?
+                    } else {
+                        write!(f, "\"\"\"{}\"\"\" ", description)?
+                    }
+                }
+            }
+        }
+        write!(f, "")
+    }
+}
+
+fn is_block_string_character(s: &str) -> bool {
+    s.contains('\n') || s.contains('"') || s.contains('\r')
+}
+#[cfg(test)]
+mod test {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn it_encodes_description_without_block_string_character() {
+        let desc = Description::Top {
+            source: Some(
+                "Favourite cat nap spots include: plant corner, pile of clothes.".to_string(),
+            ),
+        };
+
+        assert_eq!(
+            desc.to_string(),
+            r#""""Favourite cat nap spots include: plant corner, pile of clothes."""
+"#
+        );
+    }
+
+    #[test]
+    fn it_encodes_description_with_quotations() {
+        let desc = Description::Top {
+            source: Some(
+                "Favourite \"cat\" nap spots include: plant corner, pile of clothes.".to_string(),
+            ),
+        };
+
+        assert_eq!(
+            desc.to_string(),
+            r#""""
+Favourite "cat" nap spots include: plant corner, pile of clothes.
+"""
+"#
+        );
+    }
+
+    #[test]
+    fn it_encodes_description_with_new_line() {
+        let desc = Description::Top {
+            source: Some(
+                "Favourite cat nap spots include:\nplant corner, pile of clothes.".to_string(),
+            ),
+        };
+
+        assert_eq!(
+            desc.to_string(),
+            r#""""
+Favourite cat nap spots include:
+plant corner, pile of clothes.
+"""
+"#
+        );
+    }
+
+    #[test]
+    fn it_encodes_description_with_carriage_return() {
+        let desc = Description::Top {
+            source: Some(
+                "Favourite cat nap spots include:\rplant corner,\rpile of clothes.".to_string(),
+            ),
+        };
+
+        assert_eq!(
+            desc.to_string(),
+            String::from(
+                "\"\"\"\nFavourite cat nap spots include:\rplant corner,\rpile of clothes.\n\"\"\"\n"
+            )
+        );
+    }
+}

crates/sdl-encoder/src/directive_def.rs

@@ -1,4 +1,4 @@
-use crate::InputValue;
+use crate::{Description, InputValue};
 use std::fmt::{self, Display};
 
 /// The `__Directive` type represents a Directive that a service supports.
@@ -34,7 +34,7 @@ pub struct Directive {
     // Name must return a String.
     name: String,
     // Description may return a String or null.
-    description: Option<String>,
+    description: Description,
     // Args returns a Vector of __InputValue representing the arguments this
     // directive accepts.
     args: Vec<InputValue>,
@@ -48,15 +48,17 @@ impl Directive {
     pub fn new(name: String) -> Self {
         Self {
             name,
-            description: None,
+            description: Description::Top { source: None },
             args: Vec::new(),
             locations: Vec::new(),
         }
     }
 
     /// Set the Directive's description.
     pub fn description(&mut self, description: Option<String>) {
-        self.description = description;
+        self.description = Description::Top {
+            source: description,
+        };
     }
 
     /// Set the Directive's location.
@@ -72,16 +74,7 @@ impl Directive {
 
 impl Display for Directive {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if let Some(description) = &self.description {
-            // We are determing on whether to have description formatted as
-            // a multiline comment based on whether or not it already includes a
-            // \n.
-            match description.contains('\n') {
-                true => writeln!(f, "\"\"\"\n{}\n\"\"\"", description)?,
-                false => writeln!(f, "\"\"\"{}\"\"\"", description)?,
-            }
-        }
-
+        write!(f, "{}", self.description)?;
         write!(f, "directive @{}", self.name)?;
 
         if !self.args.is_empty() {

crates/sdl-encoder/src/enum_def.rs

@@ -1,4 +1,4 @@
-use crate::EnumValue;
+use crate::{Description, EnumValue};
 use std::fmt::{self, Display};
 
 /// Enums are special scalars that can only have a defined set of values.
@@ -41,7 +41,7 @@ pub struct EnumDef {
     // Name must return a String.
     name: String,
     // Description may return a String or null.
-    description: Option<String>,
+    description: Description,
     // A vector of EnumValue. There must be at least one and they must have
     // unique names.
     values: Vec<EnumValue>,
@@ -52,14 +52,16 @@ impl EnumDef {
     pub fn new(name: String) -> Self {
         Self {
             name,
-            description: None,
+            description: Description::Top { source: None },
             values: Vec::new(),
         }
     }
 
     /// Set the Enum Definition's description.
     pub fn description(&mut self, description: Option<String>) {
-        self.description = description;
+        self.description = Description::Top {
+            source: description,
+        };
     }
 
     /// Set the Enum Definitions's values.
@@ -70,16 +72,7 @@ impl EnumDef {
 
 impl Display for EnumDef {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if let Some(description) = &self.description {
-            // We are determing on whether to have description formatted as
-            // a multiline comment based on whether or not it already includes a
-            // \n.
-            match description.contains('\n') {
-                true => writeln!(f, "\"\"\"\n{}\n\"\"\"", description)?,
-                false => writeln!(f, "\"\"\"{}\"\"\"", description)?,
-            }
-        }
-
+        write!(f, "{}", self.description)?;
         write!(f, "enum {} {{", self.name)?;
         for value in &self.values {
             write!(f, "\n{}", value)?;

crates/sdl-encoder/src/enum_value.rs

@@ -1,5 +1,7 @@
 use std::fmt::{self, Display};
 
+use crate::Description;
+
 /// The __EnumValue type represents one of possible values of an enum.
 ///
 /// *EnumValueDefinition*:
@@ -26,7 +28,7 @@ pub struct EnumValue {
     // Name must return a String.
     name: String,
     // Description may return a String or null.
-    description: Option<String>,
+    description: Description,
     // Deprecated returns true if this enum value should no longer be used, otherwise false.
     is_deprecated: bool,
     // Deprecation reason optionally provides a reason why this enum value is deprecated.
@@ -39,14 +41,16 @@ impl EnumValue {
         Self {
             name,
             is_deprecated: false,
-            description: None,
+            description: Description::Field { source: None },
             deprecation_reason: None,
         }
     }
 
     /// Set the Enum Value's description.
     pub fn description(&mut self, description: Option<String>) {
-        self.description = description;
+        self.description = Description::Field {
+            source: description,
+        };
     }
 
     /// Set the Enum Value's deprecation properties.
@@ -58,16 +62,7 @@ impl EnumValue {
 
 impl Display for EnumValue {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if let Some(description) = &self.description {
-            // We are determing on whether to have description formatted as
-            // a multiline comment based on whether or not it already includes a
-            // \n.
-            match description.contains('\n') {
-                true => writeln!(f, "  \"\"\"\n  {}\n  \"\"\"", description)?,
-                false => writeln!(f, "  \"\"\"{}\"\"\"", description)?,
-            }
-        }
-
+        write!(f, "{}", self.description)?;
         write!(f, "  {}", self.name)?;
 
         if self.is_deprecated {

crates/sdl-encoder/src/field.rs

@@ -1,4 +1,4 @@
-use crate::{InputValue, Type_};
+use crate::{Description, InputValue, Type_};
 use std::fmt::{self, Display};
 /// The __Field type represents each field in an Object or Interface type.
 ///
@@ -35,7 +35,7 @@ pub struct Field {
     // Name must return a String.
     name: String,
     // Description may return a String.
-    description: Option<String>,
+    description: Description,
     // Args returns a List of __InputValue representing the arguments this field accepts.
     args: Vec<InputValue>,
     // Type must return a __Type that represents the type of value returned by this field.
@@ -50,7 +50,7 @@ impl Field {
     /// Create a new instance of Field.
     pub fn new(name: String, type_: Type_) -> Self {
         Self {
-            description: None,
+            description: Description::Field { source: None },
             name,
             type_,
             args: Vec::new(),
@@ -61,7 +61,9 @@ impl Field {
 
     /// Set the Field's description.
     pub fn description(&mut self, description: Option<String>) {
-        self.description = description;
+        self.description = Description::Field {
+            source: description,
+        };
     }
 
     /// Set the Field's deprecation properties.
@@ -78,19 +80,7 @@ impl Field {
 
 impl Display for Field {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if let Some(description) = &self.description {
-            // Let's indent description on a field level for now, as all fields
-            // are always on the same level and are indented by 2 spaces.
-            //
-            // We are also determing on whether to have description formatted as
-            // a multiline comment based on whether or not it already includes a
-            // \n.
-            match description.contains('\n') {
-                true => writeln!(f, "  \"\"\"\n  {}\n  \"\"\"", description)?,
-                false => writeln!(f, "  \"\"\"{}\"\"\"", description)?,
-            }
-        }
-
+        write!(f, "{}", self.description)?;
         write!(f, "  {}", self.name)?;
 
         if !self.args.is_empty() {