JS: support React getDerivedStateFromProps

Author: Esben Sparre Andreasen

javascript/ql/src/semmle/javascript/frameworks/React.qll

@@ -180,6 +180,8 @@ abstract class ReactComponent extends ASTNode {
         // setState with object: `this.setState({foo: 42})`
         result = arg0
     )
+    or
+    result.flowsToExpr(getStaticMethod("getDerivedStateFromProps").getAReturnedExpr())
   }
 
   /**
@@ -198,6 +200,10 @@ abstract class ReactComponent extends ASTNode {
       // componentDidUpdate: (prevProps, prevState)
       callback = getInstanceMethod("componentDidUpdate").flow() and
       stateParameterIndex = 1
+      or
+      // getDerivedStateFromProps: (props, state)
+      callback = getStaticMethod("getDerivedStateFromProps").flow() and
+      stateParameterIndex = 1
     )
   }
 
@@ -242,6 +248,10 @@ abstract class ReactComponent extends ASTNode {
       // componentDidUpdate: (prevProps, prevState)
       callback = getInstanceMethod("componentDidUpdate").flow() and
       propsParameterIndex = 0
+      or
+      // getDerivedStateFromProps: (props, state)
+      callback = getStaticMethod("getDerivedStateFromProps").flow() and
+      propsParameterIndex = 0
     )
   }
 

javascript/ql/test/library-tests/frameworks/ReactJS/ReactComponent_getACandidateStateSource.expected

@@ -1,4 +1,5 @@
 | es6.js:14:1:20:1 | class H ...     }\\n} | es6.js:18:22:18:31 | { baz: 42} |
+| rare-lifecycle-methods.js:1:1:11:1 | class C ...     }\\n} | rare-lifecycle-methods.js:3:16:3:17 | {} |
 | statePropertyReads.js:1:1:13:1 | class R ...     }\\n} | statePropertyReads.js:7:45:7:56 | prevState.p3 |
 | statePropertyWrites.js:1:1:34:1 | class W ...    };\\n} | statePropertyWrites.js:8:18:8:19 | {} |
 | statePropertyWrites.js:1:1:34:1 | class W ...    };\\n} | statePropertyWrites.js:12:18:12:19 | {} |

javascript/ql/test/library-tests/frameworks/ReactJS/ReactComponent_getAPreviousStateSource.expected

@@ -1,2 +1,3 @@
+| rare-lifecycle-methods.js:1:1:11:1 | class C ...     }\\n} | rare-lifecycle-methods.js:2:44:2:48 | state |
 | statePropertyReads.js:1:1:13:1 | class R ...     }\\n} | statePropertyReads.js:7:24:7:32 | prevState |
 | statePropertyReads.js:1:1:13:1 | class R ...     }\\n} | statePropertyReads.js:10:35:10:43 | prevState |

javascript/ql/test/query-tests/React/UnusedOrUndefinedStateProperty/UnusedOrUndefinedStateProperty.expected

@@ -2,7 +2,5 @@
 | undefined.js:1:1:1:34 | class C ...     }\\n} | Component state property 'notWrittenButReadInChain' is $@, but it is never written. | undefined.js:9:9:9:43 | this.st ... InChain | read |
 | undefined.js:32:1:32:34 | class C ...     }\\n} | Component state property 'notWrittenThrougExternalPropertyAccess' is $@, but it is never written. | undefined.js:35:9:35:57 | this.st ... yAccess | read |
 | undefined.js:61:19:61:19 | {\\n    r ... ;\\n  }\\n} | Component state property 'notWrittenInKnownInitializerObject' is $@, but it is never written. | undefined.js:64:9:64:53 | this.st ... rObject | read |
-| undefined.js:159:1:159:35 | class C ...     }\\n} | Component state property 'writeIn_getDerivedStateFromProps' is $@, but it is never written. | undefined.js:166:9:166:51 | this.st ... omProps | read |
 | unused.js:1:1:1:34 | class C ...     }\\n} | Component state property 'notRead' is $@, but it is never read. | unused.js:6:9:6:26 | this.state.notRead | written |
 | unused.js:27:1:27:34 | class C ...     }\\n} | Component state property 'notReadThrougExternaPropertyAccess' is $@, but it is never read. | unused.js:30:9:30:53 | this.st ... yAccess | written |
-| unused.js:64:1:64:34 | class C ...    }\\n\\n} | Component state property 'readIn_getDerivedStateFromProps' is $@, but it is never read. | unused.js:71:9:71:50 | this.st ... omProps | written |