lint: Move assertion linter into lint runner

On failure, this makes the output more consistent with the other linter.
Each failure will be marked with an '⚠️ ' emoji and explanation, making
it easier to spot.

Also, add --line-number to the filesystem linter.

Also, add newlines after each failing check, to visually separate
different failures from each other.

Can be reviewed with:
"--color-moved=dimmed-zebra --color-moved-ws=ignore-all-space"

test/lint/test_runner/src/main.rs

@@ -48,6 +48,16 @@ fn get_linter_list() -> Vec<&'static Linter> {
             name: "std_filesystem",
             lint_fn: lint_std_filesystem
         },
+        &Linter {
+            description: "Check that fatal assertions are not used in RPC code",
+            name: "rpc_assert",
+            lint_fn: lint_rpc_assert
+        },
+        &Linter {
+            description: "Check that boost assertions are not used",
+            name: "boost_assert",
+            lint_fn: lint_boost_assert
+        },
         &Linter {
             description: "Check that release note snippets are in the right folder",
             name: "doc_release_note_snippets",
@@ -237,7 +247,7 @@ fn lint_py_lint() -> LintResult {
             "F822", // undefined name name in __all__
             "F823", // local variable name … referenced before assignment
             "F841", // local variable 'foo' is assigned to but never used
-            "PLE", // Pylint errors
+            "PLE",  // Pylint errors
             "W191", // indentation contains tabs
             "W291", // trailing whitespace
             "W292", // no newline at end of file
@@ -273,6 +283,7 @@ fn lint_std_filesystem() -> LintResult {
     let found = git()
         .args([
             "grep",
+            "--line-number",
             "std::filesystem",
             "--",
             "./src/",
@@ -293,6 +304,62 @@ fs:: namespace, which has unsafe filesystem functions marked as deleted.
     }
 }
 
+fn lint_rpc_assert() -> LintResult {
+    let found = git()
+        .args([
+            "grep",
+            "--line-number",
+            "--extended-regexp",
+            r"\<(A|a)ss(ume|ert)\(",
+            "--",
+            "src/rpc/",
+            "src/wallet/rpc*",
+            ":(exclude)src/rpc/server.cpp",
+            // src/rpc/server.cpp is excluded from this check since it's mostly meta-code.
+        ])
+        .status()
+        .expect("command error")
+        .success();
+    if found {
+        Err(r#"
+^^^
+CHECK_NONFATAL(condition) or NONFATAL_UNREACHABLE should be used instead of assert for RPC code.
+
+Aborting the whole process is undesirable for RPC code. So nonfatal
+checks should be used over assert. See: src/util/check.h
+            "#
+        .to_string())
+    } else {
+        Ok(())
+    }
+}
+
+fn lint_boost_assert() -> LintResult {
+    let found = git()
+        .args([
+            "grep",
+            "--line-number",
+            "--extended-regexp",
+            r"BOOST_ASSERT\(",
+            "--",
+            "*.cpp",
+            "*.h",
+        ])
+        .status()
+        .expect("command error")
+        .success();
+    if found {
+        Err(r#"
+^^^
+BOOST_ASSERT must be replaced with Assert, BOOST_REQUIRE, or BOOST_CHECK to avoid an unnecessary
+include of the boost/assert.hpp dependency.
+            "#
+        .to_string())
+    } else {
+        Ok(())
+    }
+}
+
 fn lint_doc_release_note_snippets() -> LintResult {
     let non_release_notes = check_output(git().args([
         "ls-files",
@@ -593,7 +660,7 @@ fn main() -> ExitCode {
                 "{err}\n^---- ⚠️ Failure generated from lint check '{}'!",
                 linter.name
             );
-            println!("{}", linter.description);
+            println!("{}\n\n", linter.description);
             test_failed = true;
         }
     }