1 files changed, 63 insertions, 0 deletions
diff --git a/starlarkstruct/testdata/struct.star b/starlarkstruct/testdata/struct.star
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+++ b/starlarkstruct/testdata/struct.star
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+# Tests of Starlark 'struct' extension.
+# This is not a standard feature and the Go and Starlark APIs may yet change.
+
+load("assert.star", "assert")
+
+assert.eq(str(struct), "<built-in function struct>")
+
+# struct is a constructor for "unbranded" structs.
+s = struct(host = "localhost", port = 80)
+assert.eq(s, s)
+assert.eq(s, struct(host = "localhost", port = 80))
+assert.ne(s, struct(host = "localhost", port = 81))
+assert.eq(type(s), "struct")
+assert.eq(str(s), 'struct(host = "localhost", port = 80)')
+assert.eq(s.host, "localhost")
+assert.eq(s.port, 80)
+assert.fails(lambda : s.protocol, "struct has no .protocol attribute")
+assert.eq(dir(s), ["host", "port"])
+
+# Use gensym to create "branded" struct types.
+hostport = gensym(name = "hostport")
+assert.eq(type(hostport), "symbol")
+assert.eq(str(hostport), "hostport")
+
+# Call the symbol to instantiate a new type.
+http = hostport(host = "localhost", port = 80)
+assert.eq(type(http), "struct")
+assert.eq(str(http), 'hostport(host = "localhost", port = 80)')  # includes name of constructor
+assert.eq(http, http)
+assert.eq(http, hostport(host = "localhost", port = 80))
+assert.ne(http, hostport(host = "localhost", port = 443))
+assert.eq(http.host, "localhost")
+assert.eq(http.port, 80)
+assert.fails(lambda : http.protocol, "hostport struct has no .protocol attribute")
+
+person = gensym(name = "person")
+bob = person(name = "bob", age = 50)
+alice = person(name = "alice", city = "NYC")
+assert.ne(http, bob)  # different constructor symbols
+assert.ne(bob, alice)  # different fields
+
+hostport2 = gensym(name = "hostport")
+assert.eq(hostport, hostport)
+assert.ne(hostport, hostport2)  # same name, different symbol
+assert.ne(http, hostport2(host = "localhost", port = 80))  # equal fields but different ctor symbols
+
+# dir
+assert.eq(dir(alice), ["city", "name"])
+assert.eq(dir(bob), ["age", "name"])
+assert.eq(dir(http), ["host", "port"])
+
+# hasattr, getattr
+assert.true(hasattr(alice, "city"))
+assert.eq(hasattr(alice, "ageaa"), False)
+assert.eq(getattr(alice, "city"), "NYC")
+
+# +
+assert.eq(bob + bob, bob)
+assert.eq(bob + alice, person(age = 50, city = "NYC", name = "alice"))
+assert.eq(alice + bob, person(age = 50, city = "NYC", name = "bob"))  # not commutative! a misfeature
+assert.fails(lambda : alice + 1, "struct \\+ int")
+assert.eq(http + http, http)
+assert.fails(lambda : http + bob, "different constructors: hostport \\+ person")