From c18a476806c44d3d4d5e3509585d76d83c06ff92 Mon Sep 17 00:00:00 2001
From: link2xt <link2xt@testrun.org>
Date: Mon, 18 Nov 2024 22:13:14 +0000
Subject: [PATCH] refactor: forbid clippy::string_slice

---
 deltachat-contact-tools/src/lib.rs |  1 +
 deltachat-jsonrpc/src/lib.rs       |  1 +
 format-flowed/src/lib.rs           |  1 +
 src/lib.rs                         |  1 +
 src/qr.rs                          | 15 ++++----------
 src/securejoin.rs                  |  2 +-
 src/tools.rs                       | 33 ++++++++++++++++++------------
 7 files changed, 29 insertions(+), 25 deletions(-)

diff --git a/deltachat-contact-tools/src/lib.rs b/deltachat-contact-tools/src/lib.rs
index 4a6e5b037d..17c2ad0d4c 100644
--- a/deltachat-contact-tools/src/lib.rs
+++ b/deltachat-contact-tools/src/lib.rs
@@ -16,6 +16,7 @@
     clippy::cloned_instead_of_copied
 )]
 #![cfg_attr(not(test), forbid(clippy::indexing_slicing))]
+#![cfg_attr(not(test), forbid(clippy::string_slice))]
 #![allow(
     clippy::match_bool,
     clippy::mixed_read_write_in_expression,
diff --git a/deltachat-jsonrpc/src/lib.rs b/deltachat-jsonrpc/src/lib.rs
index 912a6883a7..389206f467 100644
--- a/deltachat-jsonrpc/src/lib.rs
+++ b/deltachat-jsonrpc/src/lib.rs
@@ -1,5 +1,6 @@
 #![recursion_limit = "256"]
 #![cfg_attr(not(test), forbid(clippy::indexing_slicing))]
+#![cfg_attr(not(test), forbid(clippy::string_slice))]
 pub mod api;
 pub use yerpc;
 
diff --git a/format-flowed/src/lib.rs b/format-flowed/src/lib.rs
index 055dd66778..4d246b9c07 100644
--- a/format-flowed/src/lib.rs
+++ b/format-flowed/src/lib.rs
@@ -9,6 +9,7 @@
 //!
 //! For received messages, DelSp parameter is honoured.
 #![cfg_attr(not(test), forbid(clippy::indexing_slicing))]
+#![cfg_attr(not(test), forbid(clippy::string_slice))]
 
 /// Wraps line to 72 characters using format=flowed soft breaks.
 ///
diff --git a/src/lib.rs b/src/lib.rs
index 7124bd5eb2..86c79ebdaa 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -17,6 +17,7 @@
     clippy::cloned_instead_of_copied
 )]
 #![cfg_attr(not(test), forbid(clippy::indexing_slicing))]
+#![cfg_attr(not(test), forbid(clippy::string_slice))]
 #![allow(
     clippy::match_bool,
     clippy::mixed_read_write_in_expression,
diff --git a/src/qr.rs b/src/qr.rs
index 30f0eb4e69..ed76947b0f 100644
--- a/src/qr.rs
+++ b/src/qr.rs
@@ -807,11 +807,7 @@ async fn decode_mailto(context: &Context, qr: &str) -> Result<Qr> {
         .get(MAILTO_SCHEME.len()..)
         .context("Invalid mailto: scheme")?;
 
-    let (addr, query) = if let Some(query_index) = payload.find('?') {
-        (&payload[..query_index], &payload[query_index + 1..])
-    } else {
-        (payload, "")
-    };
+    let (addr, query) = payload.split_once('?').unwrap_or((payload, ""));
 
     let param: BTreeMap<&str, &str> = query
         .split('&')
@@ -861,12 +857,9 @@ async fn decode_mailto(context: &Context, qr: &str) -> Result<Qr> {
 async fn decode_smtp(context: &Context, qr: &str) -> Result<Qr> {
     let payload = qr.get(SMTP_SCHEME.len()..).context("Invalid SMTP scheme")?;
 
-    let addr = if let Some(query_index) = payload.find(':') {
-        &payload[..query_index]
-    } else {
-        bail!("Invalid SMTP found");
-    };
-
+    let (addr, _rest) = payload
+        .split_once(':')
+        .context("Invalid SMTP scheme payload")?;
     let addr = normalize_address(addr)?;
     let name = "";
     Qr::from_address(context, name, &addr, None).await
diff --git a/src/securejoin.rs b/src/securejoin.rs
index 863d2b4f2f..96631fe01a 100644
--- a/src/securejoin.rs
+++ b/src/securejoin.rs
@@ -347,7 +347,7 @@ pub(crate) async fn handle_securejoin_handshake(
             send_alice_handshake_msg(
                 context,
                 contact_id,
-                &format!("{}-auth-required", &step[..2]),
+                &format!("{}-auth-required", &step.get(..2).unwrap_or_default()),
             )
             .await
             .context("failed sending auth-required handshake message")?;
diff --git a/src/tools.rs b/src/tools.rs
index ef460316c7..bad4cb2529 100644
--- a/src/tools.rs
+++ b/src/tools.rs
@@ -47,20 +47,27 @@ use crate::stock_str;
 /// end of the shortened string.
 pub(crate) fn truncate(buf: &str, approx_chars: usize) -> Cow<str> {
     let count = buf.chars().count();
-    if count > approx_chars + DC_ELLIPSIS.len() {
-        let end_pos = buf
-            .char_indices()
-            .nth(approx_chars)
-            .map(|(n, _)| n)
-            .unwrap_or_default();
-
-        if let Some(index) = buf[..end_pos].rfind([' ', '\n']) {
-            Cow::Owned(format!("{}{}", &buf[..=index], DC_ELLIPSIS))
-        } else {
-            Cow::Owned(format!("{}{}", &buf[..end_pos], DC_ELLIPSIS))
-        }
+    if count <= approx_chars + DC_ELLIPSIS.len() {
+        return Cow::Borrowed(buf);
+    }
+    let end_pos = buf
+        .char_indices()
+        .nth(approx_chars)
+        .map(|(n, _)| n)
+        .unwrap_or_default();
+
+    if let Some(index) = buf.get(..end_pos).and_then(|s| s.rfind([' ', '\n'])) {
+        Cow::Owned(format!(
+            "{}{}",
+            &buf.get(..=index).unwrap_or_default(),
+            DC_ELLIPSIS
+        ))
     } else {
-        Cow::Borrowed(buf)
+        Cow::Owned(format!(
+            "{}{}",
+            &buf.get(..end_pos).unwrap_or_default(),
+            DC_ELLIPSIS
+        ))
     }
 }