From aefcbda194f08682debd3b69948597e9455ca84b Mon Sep 17 00:00:00 2001
From: Matt Brown <matthewbrown@slack-corp.com>
Date: Wed, 25 Sep 2024 17:42:12 -0700
Subject: [PATCH] Fix invariant(false) handling

---
 .../expr/call/function_call_analyzer.rs       |  6 +---
 .../call/function_call_return_type_fetcher.rs |  8 +++++-
 src/analyzer/stmt/switch_analyzer.rs          | 28 ++-----------------
 .../elseWithInvariantFalse/input.hack         |  9 ++++++
 4 files changed, 19 insertions(+), 32 deletions(-)
 create mode 100644 tests/inference/FunctionCall/elseWithInvariantFalse/input.hack

diff --git a/src/analyzer/expr/call/function_call_analyzer.rs b/src/analyzer/expr/call/function_call_analyzer.rs
index f06b7c49..b4a0fe43 100644
--- a/src/analyzer/expr/call/function_call_analyzer.rs
+++ b/src/analyzer/expr/call/function_call_analyzer.rs
@@ -245,6 +245,7 @@ pub(crate) fn analyze(
     if stmt_type.is_nothing() && !context.inside_loop {
         context.has_returned = true;
         context.control_actions.insert(ControlAction::End);
+        return Ok(());
     }
 
     match name {
@@ -527,11 +528,6 @@ fn process_invariant(
     statements_analyzer: &StatementsAnalyzer,
     analysis_data: &mut FunctionAnalysisData,
 ) {
-    if first_arg.2 == aast::Expr_::False {
-        context.has_returned = true;
-        context.control_actions.insert(ControlAction::End);
-        return;
-    }
     let assertion_context = statements_analyzer.get_assertion_context(
         context.function_context.calling_class.as_ref(),
         context.function_context.calling_functionlike_id.as_ref(),
diff --git a/src/analyzer/expr/call/function_call_return_type_fetcher.rs b/src/analyzer/expr/call/function_call_return_type_fetcher.rs
index c5fcc162..d5d98800 100644
--- a/src/analyzer/expr/call/function_call_return_type_fetcher.rs
+++ b/src/analyzer/expr/call/function_call_return_type_fetcher.rs
@@ -28,7 +28,6 @@ use std::sync::Arc;
 
 use crate::expr::binop::concat_analyzer::{analyze_concat_nodes, get_concat_nodes};
 use crate::expr::fetch::array_fetch_analyzer::handle_array_access_on_dict;
-use crate::expr::variable_fetch_analyzer;
 use crate::function_analysis_data::FunctionAnalysisData;
 use crate::scope::BlockContext;
 use crate::scope_analyzer::ScopeAnalyzer;
@@ -172,6 +171,13 @@ fn handle_special_functions(
     context: &mut BlockContext,
 ) -> Option<TUnion> {
     match name {
+        &StrId::INVARIANT => {
+            if let Some((_, aast::Expr(_, _, aast::Expr_::False))) = args.first() {
+                Some(get_nothing())
+            } else {
+                None
+            }
+        }
         &StrId::TYPE_STRUCTURE_FN => {
             if let (Some((_, first_arg_expr)), Some((_, second_arg_expr))) =
                 (args.first(), args.get(1))
diff --git a/src/analyzer/stmt/switch_analyzer.rs b/src/analyzer/stmt/switch_analyzer.rs
index fd0684d0..f90b0c40 100644
--- a/src/analyzer/stmt/switch_analyzer.rs
+++ b/src/analyzer/stmt/switch_analyzer.rs
@@ -1,9 +1,7 @@
-use hakana_code_info::codebase_info::CodebaseInfo;
 use hakana_code_info::ttype::{combine_union_types, get_mixed_any};
-use hakana_str::{Interner, StrId};
+
 use indexmap::IndexMap;
 use oxidized::{aast, aast::Pos};
-use rustc_hash::{FxHashMap, FxHashSet};
 use std::rc::Rc;
 
 use crate::{
@@ -19,11 +17,7 @@ use crate::{
     stmt_analyzer::AnalysisError,
 };
 
-use super::{
-    control_analyzer::{self, BreakContext},
-    if_conditional_analyzer::add_branch_dataflow,
-    switch_case_analyzer::analyze_case,
-};
+use super::{if_conditional_analyzer::add_branch_dataflow, switch_case_analyzer::analyze_case};
 
 pub(crate) fn analyze(
     statements_analyzer: &StatementsAnalyzer,
@@ -89,8 +83,6 @@ pub(crate) fn analyze(
 
     let original_context = context.clone();
 
-    let mut last_case_exit_type = ControlAction::Break;
-
     let has_default = stmt.2.is_some();
 
     let mut cases = stmt.1.iter().enumerate().collect::<IndexMap<_, _>>();
@@ -195,19 +187,3 @@ pub(crate) fn analyze(
 
     Ok(())
 }
-
-fn get_last_action(case_actions: FxHashSet<ControlAction>) -> Option<ControlAction> {
-    if !case_actions.contains(&ControlAction::None) {
-        if case_actions.len() == 1 && case_actions.contains(&ControlAction::End) {
-            return Some(ControlAction::Return);
-        } else if case_actions.len() == 1 && case_actions.contains(&ControlAction::Continue) {
-            return Some(ControlAction::Continue);
-        } else if case_actions.contains(&ControlAction::LeaveSwitch) {
-            return Some(ControlAction::Break);
-        }
-    } else if case_actions.len() != 1 {
-        return Some(ControlAction::Break);
-    }
-
-    None
-}
diff --git a/tests/inference/FunctionCall/elseWithInvariantFalse/input.hack b/tests/inference/FunctionCall/elseWithInvariantFalse/input.hack
new file mode 100644
index 00000000..6d88cbaa
--- /dev/null
+++ b/tests/inference/FunctionCall/elseWithInvariantFalse/input.hack
@@ -0,0 +1,9 @@
+function foo(): void {
+    if (rand(0, 1)) {
+        $a = 5;
+    } else {
+        invariant(false, 'bad');
+    }
+
+    echo $a;
+}
\ No newline at end of file