support then / catch

Author: baseballyama

Diff for: src/rules/valid-context-access.ts

@@ -2,6 +2,7 @@ import { createRule } from "../utils"
 import { extractContextReferences } from "./reference-helpers/svelte-context"
 import { extractSvelteLifeCycleReferences } from "./reference-helpers/svelte-lifecycle"
 import { extractTaskReferences } from "./reference-helpers/microtask"
+import { isInsideOfPromiseThenOrCatch } from "../utils/promise"
 import type { AST } from "svelte-eslint-parser"
 import type { TSESTree } from "@typescript-eslint/types"
 
@@ -153,6 +154,11 @@ export default createRule("valid-context-access", {
         return
       }
 
+      if (isInsideOfPromiseThenOrCatch(currentNode)) {
+        report(contextCallExpression)
+        return
+      }
+
       let { parent } = currentNode
       while (parent) {
         parent = parent.parent

Diff for: src/utils/promise.ts

@@ -0,0 +1,31 @@
+import type { TSESTree } from "@typescript-eslint/types"
+
+/**
+ * Return true if `node` is inside of `then` or `catch`.
+ */
+export function isInsideOfPromiseThenOrCatch(node: TSESTree.Node): boolean {
+  let parent: TSESTree.Node | undefined = node.parent
+  while (parent) {
+    parent = parent.parent
+    if (parent?.type !== "ExpressionStatement") {
+      continue
+    }
+    const expression = parent?.expression
+    if (expression == null || expression?.type !== "CallExpression") {
+      return false
+    }
+
+    const callee = expression.callee
+    if (callee.type !== "MemberExpression") {
+      return false
+    }
+
+    const property = callee.property
+    return (
+      property.type === "Identifier" &&
+      ["then", "catch"].includes(property.name)
+    )
+  }
+
+  return false
+}

Diff for: tests/fixtures/rules/valid-context-access/invalid/case12-errors.yaml

@@ -0,0 +1,12 @@
+- message: Do not call setContext except during component initialization.
+  line: 5
+  column: 5
+- message: Do not call setContext except during component initialization.
+  line: 9
+  column: 5
+- message: Do not call setContext except during component initialization.
+  line: 13
+  column: 5
+- message: Do not call setContext except during component initialization.
+  line: 17
+  column: 5

Diff for: tests/fixtures/rules/valid-context-access/invalid/case12-input.svelte

@@ -0,0 +1,19 @@
+<script>
+  import { setContext } from "svelte"
+
+  Promise.resolve().then(() => {
+    setContext("answer", 42)
+  })
+
+  Promise.resolve().then(function () {
+    setContext("answer", 42)
+  })
+
+  Promise.resolve().catch(() => {
+    setContext("answer", 42)
+  })
+
+  Promise.resolve().catch(function () {
+    setContext("answer", 42)
+  })
+</script>