@gracexwho/model-card-generator/lib/python-program-analysis/src/test/parser.test.ts

Tool for generating model cards for Jupyter Notebook.

import * as py from "../python-parser";
import { parse, walk } from "../python-parser";

describe("python parser", () => {
  // The next two tests were because the lexer was confused about how to handle dots. It
  // couldn't read a dot followed by digits as a floating point number.
  it("can parse floats that have no digits before the dot", () => {
    parse("a = .2\n");
  });

  it("can also parse calls on objects", () => {
    parse("obj.prop\n");
  });

  it("can parse comments", () => {
    const tree = parse("#\n");
    expect(tree.code).toBeInstanceOf(Array);
    expect(tree.code.length).toBe(0);
  });

  it("can parse scientific notation", () => {
    parse("1e5\n");
  });

  it("can parse imaginary numbers", () => {
    parse("x = 12j\n");
  });

  it("can parse lambdas with keyword", () => {
    parse("f = (lambda document, **variety: document)\n");
  });

  it("parses a dictionary with a `comp_for`", () => {
    let mod = parse("{k: v for (k, v) in d.items()}\n");
    expect(mod).toBeDefined();
    let node = mod.code[0] as py.DictExpr;
    expect(node.entries.length).toBe(1);
    expect(node.comp_for).toBeDefined();
  });

  it("can parse line continuations", () => {
    parse(["a = b\\", ".func(1, 2)\\", ".func(3, 4)", ""].join("\n"));
  });

  it("produces the full location of a line for a call statement", () => {
    let node = parse(["obj.func()", ""].join("\n")).code[0];
    expect(node.location).toEqual({
      first_line: 1,
      first_column: 0,
      last_line: 1,
      last_column: 10
    });
  });

  it("does not crash on correct code after parsing bad code", () => {
    expect(() => parse("print(1\n")).toThrow();
    expect(() => parse("a + 1\nb = a\n")).not.toThrow();
  });

  it("handles docstrings", () => {
    let node = parse(
      [
        "def foo():",
        '    """',
        "    this function",
        "    does nothing",
        '    """',
        "    pass\n"
      ].join("\n")
    );
    expect(node).toBeDefined();
    expect(node.code).toHaveLength(1);
    expect(node.code[0].type).toBe("def");
    const def = node.code[0] as py.Def;
    expect(def.code).toHaveLength(2);
    expect(def.code[0].type).toBe("literal");
    expect(def.code[1].type).toBe("pass");
    const docstring = def.code[0] as py.Literal;
    expect(docstring).toBeDefined();
    expect(docstring.type).toBe("literal");
  });
});

describe("ast walker", () => {
  it("doesn't crash on try-execpt blocks", () => {
    let tree = parse(
      ["try:", "    pass", "except:", "    pass", ""].join("\n")
    );
    walk(tree);
  });

  it("doesn't crash on with-statements", () => {
    let tree = parse(
      ['with sns.axes_style("white"):', "    pass", ""].join("\n")
    );
    walk(tree);
  });
});