auUjj3Ev

1export default function transformer(file, api, options) {
2  const j = api.jscodeshift;
3  const root = j(file.source);
4
5  const removeIfUnused = (importSpecifier, importDeclaration) => {
6    const varName = importSpecifier.value.local.name;
7    if (varName === "React") {
8      return false;
9    }
10
11
12    const isUsedInScopes = () => {
13      return j(importDeclaration)
14          .closestScope()
15          .find(j.Identifier, { name: varName })
16          .filter((p) => {
17            if (p.value.start === importSpecifier.value.local.start) return false;
18            if ((p.parentPath.value.type === "Property" && p.name === "key")) return false;
19            if (p.name === "property") return false;
20            return true;
21          })
22          .size() > 0;
23    };
24
25    // Caveat, this doesn't work with annonymously exported class declarations.
26    const isUsedInDecorators = () => {  // one could probably cache these, but I'm lazy.
27      let used = false;
28      root.find(j.ClassDeclaration)
29          .forEach((klass) => {
30            used = used || (klass.node.decorators && j(klass.node.decorators)
31              .find(j.Identifier, { name: varName })
32              .filter((p) => {
33                if ((p.parentPath.value.type === "Property" && p.name === "key")) return false;
34                if (p.name === "property") return false;
35                return true;
36              })
37              .size() > 0);
38          });
39      return used;
40    };
41
42    if (!(isUsedInScopes() || isUsedInDecorators())) {
43      j(importSpecifier).remove();
44      return true;
45    }
46    return false;
47  };
48
49  const removeUnusedDefaultImport = (importDeclaration) => {
50    return j(importDeclaration).find(j.ImportDefaultSpecifier).filter((s) => removeIfUnused(s, importDeclaration)).size() > 0;
51  };
52
53  const removeUnusedNonDefaultImports = (importDeclaration) => {
54    return j(importDeclaration).find(j.ImportSpecifier).filter((s) => removeIfUnused(s, importDeclaration)).size() > 0;
55  };
56
57
58  // Return True if somethin was transformed.
59  const processImportDeclaration = (importDeclaration) => {
60    // e.g. import 'styles.css'; // please Don't Touch these imports!
61    if (importDeclaration.value.specifiers.length === 0) return false;
62
63    const hadUnusedDefaultImport = removeUnusedDefaultImport(importDeclaration);
64    const hadUnusedNonDefaultImports = removeUnusedNonDefaultImports(importDeclaration);
65
66    if (importDeclaration.value.specifiers.length === 0) {
67      j(importDeclaration).remove();
68      return true;
69    }
70    return hadUnusedDefaultImport || hadUnusedNonDefaultImports;
71  };
72
73  return root.find(j.ImportDeclaration)
74      .filter(processImportDeclaration)
75      .size() > 0 ? root.toSource(options.printOptions || { quote: "single" }) : null;
76}