From b6d55290a1e416e68bb258bb1e19861692476bd2 Mon Sep 17 00:00:00 2001
From: Geobert Quach <geobert@protonmail.com>
Date: Sun, 15 Sep 2019 18:51:34 +0100
Subject: [PATCH] feat(assists): raw string <-> usual string manipulation

Fixes #1730
---
 crates/ra_assists/src/lib.rs        |   5 +
 crates/ra_assists/src/raw_string.rs | 326 ++++++++++++++++++++++++++++
 docs/user/features.md               |  56 +++++
 3 files changed, 387 insertions(+)
 create mode 100644 crates/ra_assists/src/raw_string.rs

diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 66cf325243..756acf4153 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -96,6 +96,7 @@ mod fill_match_arms;
 mod merge_match_arms;
 mod introduce_variable;
 mod inline_local_variable;
+mod raw_string;
 mod replace_if_let_with_match;
 mod split_import;
 mod remove_dbg;
@@ -125,6 +126,10 @@ fn all_assists<DB: HirDatabase>() -> &'static [fn(AssistCtx<DB>) -> Option<Assis
         move_guard::move_guard_to_arm_body,
         move_guard::move_arm_cond_to_match_guard,
         move_bounds::move_bounds_to_where_clause,
+        raw_string::add_hash,
+        raw_string::make_raw_string,
+        raw_string::make_usual_string,
+        raw_string::remove_hash,
     ]
 }
 
diff --git a/crates/ra_assists/src/raw_string.rs b/crates/ra_assists/src/raw_string.rs
new file mode 100644
index 0000000000..59dc8d0785
--- /dev/null
+++ b/crates/ra_assists/src/raw_string.rs
@@ -0,0 +1,326 @@
+use hir::db::HirDatabase;
+use ra_syntax::{ast::AstNode, ast::Literal, TextRange, TextUnit};
+
+use crate::{Assist, AssistCtx, AssistId};
+
+pub(crate) fn make_raw_string(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let literal = ctx.node_at_offset::<Literal>()?;
+    if literal.token().kind() == ra_syntax::SyntaxKind::STRING {
+        ctx.add_action(AssistId("make_raw_string"), "make raw string", |edit| {
+            edit.target(literal.syntax().text_range());
+            edit.insert(literal.syntax().text_range().start(), "r");
+        });
+        ctx.build()
+    } else {
+        None
+    }
+}
+
+pub(crate) fn make_usual_string(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let literal = ctx.node_at_offset::<Literal>()?;
+    if literal.token().kind() == ra_syntax::SyntaxKind::RAW_STRING {
+        ctx.add_action(AssistId("make_usual_string"), "make usual string", |edit| {
+            let text = literal.syntax().text();
+            let usual_start_pos = text.find_char('"').unwrap(); // we have a RAW_STRING
+            let end = literal.syntax().text_range().end();
+            dbg!(&end);
+            let mut i = 0;
+            let mut pos = 0;
+            let mut c = text.char_at(end - TextUnit::from(i));
+            while c != Some('"') {
+                if c != None {
+                    pos += 1;
+                }
+                i += 1;
+                c = text.char_at(end - TextUnit::from(i));
+            }
+
+            edit.target(literal.syntax().text_range());
+            edit.delete(TextRange::from_to(
+                literal.syntax().text_range().start(),
+                literal.syntax().text_range().start() + usual_start_pos,
+            ));
+            edit.delete(TextRange::from_to(
+                literal.syntax().text_range().end() - TextUnit::from(pos),
+                literal.syntax().text_range().end(),
+            ));
+        });
+        ctx.build()
+    } else {
+        None
+    }
+}
+
+pub(crate) fn add_hash(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let literal = ctx.node_at_offset::<Literal>()?;
+    if literal.token().kind() == ra_syntax::SyntaxKind::RAW_STRING {
+        ctx.add_action(AssistId("add_hash"), "add hash to raw string", |edit| {
+            edit.target(literal.syntax().text_range());
+            edit.insert(literal.syntax().text_range().start() + TextUnit::from(1), "#");
+            edit.insert(literal.syntax().text_range().end(), "#");
+        });
+        ctx.build()
+    } else {
+        None
+    }
+}
+
+pub(crate) fn remove_hash(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let literal = ctx.node_at_offset::<Literal>()?;
+    if literal.token().kind() == ra_syntax::SyntaxKind::RAW_STRING {
+        if !literal.syntax().text().contains_char('#') {
+            return None;
+        }
+        ctx.add_action(AssistId("remove_hash"), "remove hash from raw string", |edit| {
+            edit.target(literal.syntax().text_range());
+            edit.delete(TextRange::from_to(
+                literal.syntax().text_range().start() + TextUnit::from(1),
+                literal.syntax().text_range().start() + TextUnit::from(2),
+            ));
+            edit.delete(TextRange::from_to(
+                literal.syntax().text_range().end() - TextUnit::from(1),
+                literal.syntax().text_range().end(),
+            ));
+        });
+        ctx.build()
+    } else {
+        None
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::helpers::{check_assist, check_assist_not_applicable, check_assist_target};
+
+    #[test]
+    fn make_raw_string_target() {
+        check_assist_target(
+            make_raw_string,
+            r#"
+            fn f() {
+                let s = <|>"random string";
+            }
+            "#,
+            r#""random string""#,
+        );
+    }
+
+    #[test]
+    fn make_raw_string_works() {
+        check_assist(
+            make_raw_string,
+            r#"
+            fn f() {
+                let s = <|>"random string";
+            }
+            "#,
+            r#"
+            fn f() {
+                let s = <|>r"random string";
+            }
+            "#,
+        )
+    }
+
+    #[test]
+    fn make_raw_string_not_works() {
+        check_assist_not_applicable(
+            make_raw_string,
+            r#"
+            fn f() {
+                let s = <|>r"random string";
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn add_hash_target() {
+        check_assist_target(
+            add_hash,
+            r#"
+            fn f() {
+                let s = <|>r"random string";
+            }
+            "#,
+            r#"r"random string""#,
+        );
+    }
+
+    #[test]
+    fn add_hash_works() {
+        check_assist(
+            add_hash,
+            r#"
+            fn f() {
+                let s = <|>r"random string";
+            }
+            "#,
+            r##"
+            fn f() {
+                let s = <|>r#"random string"#;
+            }
+            "##,
+        )
+    }
+
+    #[test]
+    fn add_more_hash_works() {
+        check_assist(
+            add_hash,
+            r##"
+            fn f() {
+                let s = <|>r#"random string"#;
+            }
+            "##,
+            r###"
+            fn f() {
+                let s = <|>r##"random string"##;
+            }
+            "###,
+        )
+    }
+
+    #[test]
+    fn add_hash_not_works() {
+        check_assist_not_applicable(
+            add_hash,
+            r#"
+            fn f() {
+                let s = <|>"random string";
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn remove_hash_target() {
+        check_assist_target(
+            remove_hash,
+            r##"
+            fn f() {
+                let s = <|>r#"random string"#;
+            }
+            "##,
+            r##"r#"random string"#"##,
+        );
+    }
+
+    #[test]
+    fn remove_hash_works() {
+        check_assist(
+            remove_hash,
+            r##"
+            fn f() {
+                let s = <|>r#"random string"#;
+            }
+            "##,
+            r#"
+            fn f() {
+                let s = <|>r"random string";
+            }
+            "#,
+        )
+    }
+
+    #[test]
+    fn remove_more_hash_works() {
+        check_assist(
+            remove_hash,
+            r###"
+            fn f() {
+                let s = <|>r##"random string"##;
+            }
+            "###,
+            r##"
+            fn f() {
+                let s = <|>r#"random string"#;
+            }
+            "##,
+        )
+    }
+
+    #[test]
+    fn remove_hash_not_works() {
+        check_assist_not_applicable(
+            remove_hash,
+            r#"
+            fn f() {
+                let s = <|>"random string";
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn remove_hash_no_hash_not_works() {
+        check_assist_not_applicable(
+            remove_hash,
+            r#"
+            fn f() {
+                let s = <|>r"random string";
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn make_usual_string_target() {
+        check_assist_target(
+            make_usual_string,
+            r##"
+            fn f() {
+                let s = <|>r#"random string"#;
+            }
+            "##,
+            r##"r#"random string"#"##,
+        );
+    }
+
+    #[test]
+    fn make_usual_string_works() {
+        check_assist(
+            make_usual_string,
+            r##"
+            fn f() {
+                let s = <|>r#"random string"#;
+            }
+            "##,
+            r#"
+            fn f() {
+                let s = <|>"random string";
+            }
+            "#,
+        )
+    }
+
+    #[test]
+    fn make_usual_string_more_hash_works() {
+        check_assist(
+            make_usual_string,
+            r###"
+            fn f() {
+                let s = <|>r##"random string"##;
+            }
+            "###,
+            r##"
+            fn f() {
+                let s = <|>"random string";
+            }
+            "##,
+        )
+    }
+
+    #[test]
+    fn make_usual_string_not_works() {
+        check_assist_not_applicable(
+            make_usual_string,
+            r#"
+            fn f() {
+                let s = <|>"random string";
+            }
+            "#,
+        );
+    }
+}
diff --git a/docs/user/features.md b/docs/user/features.md
index 1034a51172..93e565315e 100644
--- a/docs/user/features.md
+++ b/docs/user/features.md
@@ -445,6 +445,62 @@ fn foo<T: u32, F: FnOnce(T) -> T>() {}
 fn foo<T, F>() where T: u32, F: FnOnce(T) -> T {}
 ```
 
+- Make raw string
+
+```rust
+// before:
+fn f() {
+    let s = <|>"abcd";
+}
+
+// after:
+fn f() {
+    let s = <|>r"abcd";
+}
+```
+
+- Make usual string
+
+```rust
+// before:
+fn f() {
+    let s = <|>r#"abcd"#;
+}
+
+// after:
+fn f() {
+    let s = <|>"abcd";
+}
+```
+
+- Add hash
+
+```rust
+// before:
+fn f() {
+    let s = <|>r"abcd";
+}
+
+// after:
+fn f() {
+    let s = <|>r#"abcd"#;
+}
+```
+
+- Remove hash
+
+```rust
+// before:
+fn f() {
+    let s = <|>r#"abcd"#;
+}
+
+// after:
+fn f() {
+    let s = <|>r"abcd";
+}
+```
+
 ### Magic Completions
 
 In addition to usual reference completion, rust-analyzer provides some ✨magic✨